I remembered that we have something similar. Turns out this military museum belongs to a private company, a metalworks. And the factory stands near Kecel in the middle of the Danube-Tisa interfluve.
The park's area 3 hectares (~30000 m2), besides the equipment they exhibit statues too. One of the buildings houses a small arms museum and a plastic models exhibition. Actually not sure all of em are plastic. I've never been here (I visited ZMNE however, it's uh, military uni basically, they also had some weaponry all about in the courtyard, way less numerous ofc, to my knowledge before that it also served as an army base with barracks for conscripts too), but the prices of entry tickets seem very reasonable, $5 for an adult.
Some more pics can be found here:
http://pintermuvek.hu/hadtechnikai-park/
I'll search the net for more. I'm sleepy as fuck now for that.

I think there is at least one more somewhere else.