Let me just also say at the outset that this issue of British use of the P-40F/L / Merlin engine types is a very tricky one to nail down. I
Kittyhawk IIA = P-40F, Kittyhawk II = P-40L, 100 F (short tail), 56 L-5 and 44 L-10 (both long tail) models, delivered in US for RAF, F from April to July 1942, L January to March 1943, 2 F to UK, 21 F lost at sea leaving 227 for the Middle East. The P-40F long tail came with the -5 block, in August 1942, all up 512 long tail F versions, 699 short tail.
US export P-40F for UK, starting with 38 in May 1942, Takoradi reports end July 1942 total 124 Kittyhawk I sent, still 124 Kittyhawk sent end September, October saw 46 Kittyhawk II sent. October 2 Kittyhawk II, 23 III. Kittyhawk were also being shipped directly to Egypt from the US.
Then comes possible distribution in the Middle East between RAF, RAAF and SAAF squadrons. Strength return 30 September 1942, 13 Kittyhawk II in squadrons, 9 in store/repair, 1 in a conversion unit. As of 31 October it was 19 in squadrons, 32 store/repair, as of 30 November it was 25 in squadrons, 90 store/repair, 7 lost during the month, total 122 out of 127 F models reported sent to Middle East, note no break down of losses by mark in September and October.
Looking through Shores et al, 260 squadron was using Kittyhawk I in September 1942, squadron records use Kittyhawks without mentioning serials or marks until 21 August when Kittyhawk (P-40F) appears, by the look of things after that come a few entries with II suggesting they are mark II. For September the mark numbers are made clear and mark II are the majority, in October only mark II sorties.
RAF Squadrons by Jefford, 260 squadron,
Kittyhawk I February to September 1942 (plus some Tomahawks until March) replacing Hurricanes
Kittyhawk II June 1942 to May 1943
Kittyhawk III December 1942 to March 1944.
There was a general upheaval of aircraft allocations through 1942, as the US entered the war and needed to support units in combat. One attempt to reset things was [Washington,] 21 June 1942. Memorandum of Agreement Between Lt. Gen. Arnold, Rear Admiral Towers and Air Chief Marshal Portal. No one stuck exactly to the agreements.
But part of the problem was also due to the specific details of the licensing agreement between Rolls Royce and Packard, which only produced a relatively small number of the Merlin 28 / XX copy / V-1650-1 types, and a certain number of these had to go to Canada for British aircraft types (most ended up not seeing combat, I think) with the bulk of Packard-Merlin production going to the Merlin 60 series for the P-51 (and some other types).
Licensing had nothing to do with the quantity ordered/built.
To switch to the Ministry of Aircraft Production figures for US Merlins, 12,292 built to end 1943 (the US says 12,295, 1 less in April, 4 more in July 1943), 5,200 Merlin 28 from August 1941 to February 1943, 480 Merlin 29 for Canada, 560 Merlin 31 from March 1942 to February 1943, 800 Merlin 33 April to October 1943, 6,862 Merlin 38 from March 1943 with production ongoing, plus 16 two stage engines, all for the Commonwealth while the US received 2,813 one stage August 1941 to March 1943 and 2,781 two stage (5 November/December 1942, then from March 1943). The US 1 stage were mostly for the 2,011 P-40F and L, or about a 40% reserve, engine and airframe orders matched.
Canada received 309 Merlin 28, all were exported to Britain, either as stand alone or attached mostly to Hurricanes but some Lancaster, any arriving attached to Hurricanes, apart from some test flights, were removed and attached to Lancasters. UK Merlin 28 imports are reported to have ceased in July 1943, 5,165 shipped, 228 lost at sea, 4,937 arrivals.
Packard ceased 1 stage Merlin production in December 1944, by end August 1945 it had built 24,053 one stage and 30,661 two stage Merlins. Continental added another 797 two stage August 1944 to June 1945.
It's a bit confusing because of course Kittyhawk III to the British could mean the P-40M (rated for lower boost but with a higher performance ceiling of around 17,000 ft) or the P-40K
Mark III, 191 K-1 (the export version of the K, not really a block number) 52 K-5 (short fuselage), 46 K-10 (long fuselage introduced, September 1942), 50 K-15, 50 M-5, 44 M-10, the K delivered in the US June to November 1942, the M December 1942/January 1943. N model deliveries began in May 1943. Mark III distribution, 420 Middle East, 8 lost at sea, 5 SAAF (the latter cargo off loaded from a damaged ship)
Curtiss built 600 K-1, 200 K-5, 335 K-10, 165 K-15.
RAF serial FL2xx or FL3xx P-40F, FL7xx, FL8xx, FL9xx, FR111 to 115, FR2xx, FR3xx to 361 P-40K-1, FR116 to 140, FR385 to 392, 412, 413 K-5, FR414 is a K-10, the start of long tails, K-15 end at FR521, FR7xx, FR8xx P-40M, FS4xx P-40L.
RAF Census, Middle East Kittyhawk strength / lost overseas (mostly Middle East)
Feb-43 Mark I 207/284, Mark IA 174/83, Mark IIA 105/41, Mark III 202/73
Mar-43 Mark I 202/289, Mark IA 168/89, Mark IIA 94/51, Mark III 178/89
Apr-43 Mark I 199/?, Mark IA 166/?, Mark IIA 116/?, Mark III ?/98, page missing from report.
May-43 Mark I 198/293, Mark IA 166/91, Mark IIA 128/61, Mark III 208/100
Jun-43 Mark I 171/298, Mark IA 164/93, Mark IIA 129/59, Mark III 219/113
Jul-43 Mark I 170/299, Mark IA 163/94, Mark IIA 134/64, Mark III 218/117, Mark IV 14/5
Aug-43 Mark I 157/316, Mark IA 160/97, Mark IIA 130/68, Mark III 214/121, Mark IV 63/8
Sep-43 Mark I 157/316, Mark IA 160/97, Mark IIA 141/69, Mark III 227/134, Mark IV 135/14
Oct-43 Mark I 153/320, Mark IA 160/97, Mark IIA 144/70, Mark III 226/135, Mark IV 129/15
Nov-43 Mark I 153/320, Mark IA 155/102, Mark IIA 164/80, Mark III 219/148, Mark IV 126/26
Dec-43 Mark I 153/320, Mark IA 155/102, Mark IIA 165/79, Mark III 217/150, Mark IV 135/27
Jan-44 Mark I 166/307, Mark IA 156/100, Mark IIA 178/66, Mark III 239/128, Mark IV 329/30, aircraft with Dominion Air Forces now excluded.
Feb-44 Mark I 148/325, Mark IA 154/102, Mark IIA 175/71, Mark III 236/131, Mark IV 370/36
Mar-44 Mark I 94/379, Mark IA 105/151, Mark IIA 161/85, Mark III 229/138, Mark IV 414/49
Apr-44 Mark I 90/381, Mark IA 103/153, Mark IIA 161/85, Mark III 227/140, Mark IV 406/57
May-44 Mark I 62/409, Mark IA 96/160, Mark IIA 125/121, Mark III 171/196, Mark IV 388/76
Jun-44 Mark I 56/415, Mark IA 91/165, Mark IIA 123/123, Mark III 158/209, Mark IV 360/105
Anyway, the British rated the longer tails specifically regarding the stability issue. The Squadron book says they phased out the short tailed types and gave them to the French
As of end 1944 the US noted 23 P-40F and 40 P-40L transferred from Britain to France, no mention of K models., the US tracked the movements because there had to be a post war settlement.