Tracks?

www.Backyard Armor.com - Genuine Kenny Kong ones, in a few different types.

As for the gun, you can lay out the assemblies and 'test' it before you install it. I did it for my Sherman.

The traverse motor ran both ways, elevation crank arm moved up and down, cannon flashed, MG fired, lights lit up and turned off... and then I busted a light bulb installing the blasted things.

Now I'm waiting on some replacements before the beast is ready to run again,