Hi Erik
"Even just mentioning the cannon used narrows it down to just a few tanks" - hope that means it's not the 152mm Shillelagh, as Tamiya seem to have that covered now? Unless youre talking M60A2?
M48 & M60,& M1 are also already covered, which leaves M47?
Clark on his Facebook page is working on M113 (a good candidate for sales - so many countries use them & loads of variants & fairly small) & mentions that M41 will be worked on after that.
Mal