No, it most likely a M4A1(76)E2W. The 17 pounder in the Firefly's had a rounded muzzle brake. The hull is cast not welded making it most likely an M4A1. It has the larger turret for the 76mm gun making it most likely a M4A1(76). The suspension is the horizontal Volute Spring Suspension type making it the M4A1(76)E2W. Most of the modified suspensions were made after the war and sold to other countries. The American 76mm, very similar in performance to the 17 pounder. But this is not a firefly. Three of the things that mark the Firefly is the long gun with a rounded muzzle brake not the square brake as seen here. A box on the back of the turret for the radio because the breach and recoil used up what little space there was in the turret. Last is the suspension. They had the Vertical Volute Spring suspension. While most of the 1,700-2,100 Firefly's made were based on the M4A3 and M4A4 because they were the most numerous tanks lend-leased to the British. The American 76mm armed Shermans were on the way but it was a long supply line.
By the way the British used the American made Sherman because it was better than any other allied (British) tanks in numbers, mechanical reliability and armor.
the M-26 Super Pershing is my favorite... it was a pershing tank, with added frontal armor, and a more powerful 90mm gun. the M-26 Was the answer to the tiger, it had just as powerful a gun as the tiger, but better frontal armor, it was just as thick with greater slope...
the super persing was the american opponent of the King tiger, with thicker armor up frunt with a additional armor plate, with improved slope, the longer 90mm gun allowed probably a higher muzzle velocity, but with only two built it made no impact.
Hah, thanks! I wasn't even going to upload this one since it didn't look too special to me (which is why it's in the 'scraps' folder, but I suppose i'll change that), but i'm surprised people seem to like it, it's one of my most favourited photos