End-of-war German OOB

[Marcello]

There should be several Hetzer around.One of them is unit n. 28 in the Hungary OOB.The Stug IV isn't actually in the game as an unit (or at least I never saw it) but the icon is provided, n. 2089.

Next best thing is checking the file WINSPMBT_MasterIconList, which (at least in my computer) can be found here:
C:\Program Files\Shrapnel Games\The Camo Workshop\WinSPMBT\Game Data\Design
Using a search function you can find what you need. Note that the naming of the icons follow very inconsistent patterns, so you will have to be creative with the search function.

"I'm sort of shocked no one has a mod for SPMBT allowing for WW2 to continue longer"

Because both SPWAW and SPWW2 can deal with "longer WW2" in a more effective manner, as they are designed to deal with WW2 in first place.The icons available in SPMBT are here to represent the limited postwar usage of german WW2 armor, from the french love affair with the Panther to the syrian PZ IV soldiering on until the six days war, to the postwar production of the Hetzer and haltracks. As such most of the mid-late war stuff is here but some important elements are missing, like the Tiger.