Pay attention to the contact points for the keys, pedals, etc. Some Hammond organs use a fine PGM wire for each key. I'm in the middle of tearing apart a late 1960's Lowrey organ and it's key contacts arrangement is a series of long spring coil wires that appear to be silver or silver plated - I haven't pinned it down yet. If you search on the site goldrefiningforum.com you'll find more details about the use of PGM's in Hammond organs.