I believe this vacuum is an AirServ 24? This was an interesting vacuum setup.
The coin box location is welded shut, and has no bars or locks (first two pictures). The third picture is how the vacuum is bolted to the concrete slab.
These special nuts are used to fasten the stainless steel dome. The last two pictures are the slab the vacuum was mounted on and the two holes are for dropping the assembled vacuum in place?