The Allied Mediterranean Air Forces put out weekly/10 day strength reports by models, the ones I have, 15th Air Force P-38 units,
27-Feb-44, 7 F, 85 G, 38 H, 1st FG has the H models
1-Apr-44, 8 F, 85 G, 2 5H, 61 J, 1st has the H, 14th and 82nd the J
29-Apr-44, 7 F, 73 G, 24 H, 159 J
3-Jun-44, 2 F, 44 G, 4 H, 211 J
24-Jun-44, 2 F, 42 G, 3 H, 222 J
1-Jul-44, 2 F, 41 G, 4 H, 228 J
27-Jul-44, 36 G, 3 H, 191 J
2-Sep-44, 119 J, 5 L
30-Sep-44, 167 J, 73 L
P-51,
31st FG to 15th Air Force 1 April 1944, first MTO Merlin P-51 operation 16 April.
52nd FG, to 15th Air Force 1 May 1944, first operation 10 May.
325th FG, goes from 77 P-47D on strength 29 April 1944 to 3 P-47D, 46 P-51B, 38 P-51C on 3 June, Last P-47 operation 24 May, 1st P-51 operation 27 May.
332nd FG reported as converting to P-47 starting as early as April 1944 but only P-47D on strength 24 June, last P-47 operation 30 June, on 1 July had 72 P-47D, 37 P-51B and 30 P-51C, first P-51 operation on 4 July 1944.
On 29 April 1944 the 15th Air Force P-51 units held 72 P-51B, on 3 June it was 171 B and 47 C, on 22 June it was 166 B, 66 C and 53 D