Mark, Hi, It is worthwhile remembering that both American, and German Tank fixtures and fittings were common to most types which means a quick trawl through both aftermarket upgrades and reference Photographs will identify a lot of what you might need is available already whilst being sold for another model.
I am reminded of British Armour both tracked as well as wheeled and some soft skinned vehicles from the 50s to the 70s almost all of which shared engine and gearbox parts within the B-40/B-80 range, For instance a Piston or a Distributer cap for a 4 cylinder Austin Champ 1/4 tonne General Purpose vehicle engine would fit an 8 cylinder engined Saladin or Saracen armoured vehicle Indeed virtually every gearbox and engine part was inter- changeable except engine blocks and gearbox casings
Shaun.