I think it might turn into a boondoggle trying to cut down the A-arm skids of the wide 800 to fit the 50". There's a two hole plate on the inside beside the king pin tube of the 800 wide, that apparently Iron Baltic uses for the inner mounting points. That plate doesn't exist on the 50". Also there are diagonal mud drain slots going right across where one needs to cut to cut down the inner length. Cutting there would leave an abomination.

The rear, might get away with it. The front, I doubt it.
Just looking at parts diagrams there doesn't seem to be a viable direct replacement for A-arm guards by Iron Baltic for other machines like the 600's, they look way different.
Ordering a main Iron Baltic skid plate by itself might be an option. If the price is right.