So, you have a rare one it seems. Did you happen to score a pair of them? Or, just the one?
Looks like it is in great shape and thd chrome bezel is in nice shape too!
Gaskets can be made from an RTV designed for that task, not a Ultra Black/Blue/etc. product but a gasket and seal RTV.
A pair could be enticing to someone doing a 40s or custom street rod.
You might be able to sell it to a street rod shop if you have a pair.
You have good luck finding some interesting things and smoking deals.
David