Son of a b*itch, I just threw this away last night.
I have a painted speaker cover with bolts and red coin box cross bar (painted) as well if you need it.
The picture OP posted is from a taito SI cabaret.... Correct me if I'm wrong, but you parted a midway SI upright?
@OP be glad you have that cash box door, for the simple fact that taito didn't hinge it and they are always lost. Best bet is to just come up with something that the coins can fall into.
*edit* just re-read that you don't have the door.

hmmmm, good luck with that. I know there was a guy on klov that had some of those reproduced (pman
http://www.andysarcade.net/store/index.php ) not sure if he has any. But cool guy and can't hurt to reach out to him.
good day.