If we're solely talking about the distribution that was observed in the usa (which was a murky world/wild west all on its own anyway), the mv 1 models were distributed as kits used for conversion and were also sold as dedicated single-slot cabs. In addition to the official big red cabs that you could get from SNK, companies like "Dynamo" made a ton of their own dedicated cabinets using these kits that they sold/distributed.
Here is an example ad for an official single-slot cab:
View attachment 46311
There were also some interesting dedicated cabs like some made for Samurai Shodown II.
If you went with the kit, just as madman said, there was no plexi. You had to supply your own cabinet and could cut/trim/cover the cpo yourself.
I also want to add that, in some cases, the cabinets made by these other companies led to some pretty...er...inventive layouts for the 4 button setup.