>>5915556Is the one in pic related?
The base tank is a mark IV male, takom and tamiya have kits so the base (and I would say 80% of the build) is already done. The turret looks like one from an early churchill tank or something like that. Overall doesn't seem a really difficult job if you have medium level modeling knowledge as most of the things are flat and can be done with plasticard.
This dude scratch builded one in 1:18
http://www.nicksmodeltanks.com/wwi.htm