I like the Locust, also the odd ( and awful ) Marmon-Herrington light tanks*, which I gather saw
some service in the Aleutians. And I keep thinking that some variation of the 'Skeleton tank'
might be a fun build, as would the first US Heavy tank design, ( 2 X 75mm, 1 X 37 mm, and 1 X 20mm,
beaucoup machine guns ) for which, as far as I can tell, no drawings exist.
* Steve Zaloga did an excellent scratch build of one - I'll see if I can dig it up.