dont remember seeing this posted before so if it has , my apologies..but if not
boy does it look in good shape !
with the serial number i guess it's british Mk1X
http://www.youtube.com/watch?v=wWn7_5hPSI0
and a longer video here
http://www.youtube.com/watch?v=3YxcxQ9IUg0
on a Polish news site.. you can see the data plate clearly.. T=122834 built- Feb 1943 ser=4521
and anothe Polish site with the tank in a museum slightly cleaned up and with some stuff found inside. Lots of polish interviews..if anybody speaks Polish.. Seems to be in a smallish rather mixed museum workshop ...a plane, coupls trucks..other tanks. Lots of interviews..next video has much more of tank insides
http://www.youtube.com/watch?v=NLJPXjSgM6Q
This one shows the same place..looks like a workshop ..many more images of the tank although listed as a Mk III for some reason. This one shows the gun as 6pdr No1 Mk1 and seems to say RBG and No V846
When they remove periscope it clearly shows "PERISCOPE TANK INFANTRY MkIII REL CANADA 1942 3876-C
http://www.youtube.com/watch?v=NLJPXjSgM6Q