Mirror Models has released a full plastic kit of the Artillery Tractor T-20, which saw service with the Finnish, German and Russian and Romanian Armies (Decals provided for the first 3 armies).
This kit has over 450 plastic parts and it includes some small PE details. The tracks are of the “individual link” style. I don’t think they will “click” to each other; rather glue should be used in each link.
The kit includes a complete engine, engine bay, firewall and transmission. There is no “hull”, it is built from individual pieces, and so careful alignment there will be needed. Once the engine and engine bay plus basic hull is completed, assembly moves into the interior, with nicely detailed seats for the artillery gun crew.