I tried locating a Base I could possibly resize and use for a few mini's that did not have any I found.

No luck finding any. So I just did a VERY Basic design in Fusion 360

Tiny, Small, Medium 26mm (1") Base
Large 51mm (2") Base
Huge 76mm (3") Base
Gargantuan 112mm (4") Base

Bases also have a 1mm Fillet around the top edge so it's not sharp and looks better.