The upright and cabaret monitor shrouds are different, the upright is fairly equal on the top and bottom depth, the cabaret has a much larger depth at the top, and much less at the bottom.
I salvaged the original from my mini to use as a pattern, since it was ruined when some op converted the game to Capcom Bowling. Poster board was too flimsy, so I went with a lighter weight matte board and it worked great.
Just be sure to use a brand new blade in your knife, and score the folds on the front side.