1930-31 Quail Cap Repair for the Challenged!
 

I have an original Stanco quail cap and base which are not attached together. Looking at the underside of the quail cap there is a recessed hole in the center which appears to be threaded. The hole is about 1/2 inch wide. The base has the hinged piece attached, what is missing is the thin brass plate and center lug? which attaches it to the hinged piece on the base and allows it to swivel. Can someone who has worked on quail caps identify and explain the two missing pieces and suggest a workaround?