I also popped into Model Zone for quick look around and came out with a couple of airfix kits that were on sale, £1.99 for this little WWI tank
and £15.00 for this beast of a kit:
I think the Russian BMP should be easily apocalytic-iffied, it is a little on the large size (1:35 scale) but looking at the seating on the sprues they look about right for a 28mm arse.
As I've not put together any airfix kits for about 15 years I started with the WWI male tank and with a little tweaking ended up with a mini one man post apocalyptic flame tank. Most of the additions are Ramshackle games resin parts and a little extra plasticard.