After work thrift store score!
All of the military stuff was in a box together for $14.99 (more than I wanted to pay, but took a chance on it as most of the contents were not visible behind the vehicles). The camo tank is Chap Mei "Soldier Force" (90s) and is complete aside from missing the projectile for the spring-loaded launcher. The solid green tank is from "Processed Plastics" (80s?) and is intended for little green army men and is in excellent condition aside from the stickers showing some edge wear (I am debating keeping this and modifying it for 3.75" use, or selling it to a collector). The jeep is Lanard "The Corps!" (Dated 1994) and appears mostly complete (depending on which version of this was issued at what time as they varied the amount and style of accessories with different sized sets). The figures are a mix of 21st Century Toys "World War II" (2 Germans and 8 Americans), 1st generation Chap Mei "Soldier Force", and some 2000s "G.I.Joe". There were also some assorted green army men scale diorama pieces and other assorted items in the box that i have no need of (pictured in the comments).
The little space shuttle with pod was $1.99, and can be modified for 3.75" use (at least the shuttle, the pod isn't large enough to accommodate a standard figure and will be used for a tiny alien figure).