Actually nothing was removed. Just the FM-1 ( RN Martlet V/ Wildcat V ) had the two MGs per a wing installed like the F4F-3. The wing structure was slightly changed in order to accomodate the different ammo feeding system. It means that the wing skin panels got the different layout.
Below there are two images I found via the net. The first one shows the one of the first FM-1s ( believing the caption) while the second one the British Martlet V s/n. JV337. As memo serves there were small teardrop-shaped fairings behind each of the shell ejection port for each of the MG installed. Can you see the layout and the number of the bulges? If you can, you already know which guns were installed for the RN Wildcat Vs.
View attachment 713790
View attachment 713791
the pic source: the net.
I believe the first 10 FM-1's had the typical F4F-4 six guns armament. After those, the rest were equipped with just four guns.
That's okay then as looking at the RAF Serial Number Register I think mine was the 110th production as a Mk.V Wildcat for the FAA.
Contract 99036, 18 April 1942, for 1,150 FM-1 (311 for RN) with P&W R-1830-86
Contract NOa(s)-227 (99036), 31 December 1943, for 4,100 FM-2 (340 for RN) plus another 1,423 in 1945 of which 746 were cancelled, with Wright R-1820-56/72W in 1943, -72W only in 1944, -56W in 1945, a total of 4,777 built.