1961 catalogue page states 531 , 1956 says customers choice of tubing, in several previous posts on 59’s say choice of tubing, just wondering.
Ordered provenance report on it day I received it will be interesting to see what it says.
Use those two links often researching Paramounts, considering summiting a few of mine to add to his registry.
There is a 59 on Ebay, good paint, bad chrome, optimistic price.