So, here we have a B80. No doubt. You may be right, el-me-se isn't complete, at least. My King and B100 don't fit in the description there. I persume, my King is a model "in between" and the cab is a very, very early one. Maybe your B80 is a late one and might be an early B100, though.
Restauration is exactly, what my Dynacords need, but it's hard to find the right materials. I decided to leave them just as they are. Time has left some marks on them and on me too ;-) I like the fact, that my cab is as old as me, and the King ist as old as my Queen. We all wear some scars ...
Back to your problem: on top of your cab, two holes can be seen. That's where the screws go in, which connect the amp with the cab. Strange kind of engineering ...
Cheers
John