I am Kun, member of a start up company ravenworks. We are planning to develop a turn base modern war game with a bit of manga twist. I will need to illustrate 15 types of units for each of the items such as BMT tanks, APC, infantry, attack helicopters, artillery etc. There will be a hundred of illustration needed. Can you contact me on firstname.lastname@example.org.
I know this comment is old, but I feel like answering: this seems to be a Sherman Firefly from 2nd Warsaw Armoured Brigade of Polish Armed Forces in the West. The yellow name Rycerz I on its side is Polish for Knight I.
As Kogr pointed out, ony one in 4 tanks had the 17 pounder uprated gun which was longer, so they painted the front to hide it from a distance to stop them being targeted first. Possibly one of the most powerful tank guns in large circulation when it was origionaly put on the firefly.