Tank Of The Day.

Two pictures of two different Sherman Tanks.
The one at the top, 'Michael', never saw action; it was the very first lend-lease M4 to reach Britain, and was put on public display.
Note the rounded hull design, due to the fact that it was cast.
The later version below has the boxy, welded hull.
I can't be sure because the gun goes out of frame, but it may well be the Sherman Firefly equipped with the 17-Pounder anti-tank gun, reputedly the best allied anti-tank gun of the war.