One of these just sold on ebay the other day - I was wanted it and was watching it, but then let the auction slip my mind and lost it. #I don't suppose this is could be the one you bought, since the auction just ended yesterday PM: #<a href="http://cgi.ebay.com/1968-Rare-Vintage-Monterey-Harmony-F-hole-Mandolin-LR_W0QQitemZ7385402322QQcategoryZ10179Q
QssPageNameZWDVWQQrdZ1QQcmdZViewItem" target="_blank">Harmony H417</a>.
This seller described this as a model 417, with spruce top, which he claimed was only put out in 1968. #I don't know if that's true, but I do know, from looking at dozens of Harmony archtops mandolin auctions, that the solid spruce topped ones are rarely seen - I've only seen one or two others. #The vast majority, like the Harmony archtop guitars, were solid "genuine hardwood", many flame-painted like Paul's above. #Although, I recently got a rare solid spruce top Harmony flattop mandolin, but to my surprise it does appear to have a laminated back. #Each of my several Harmony guitars has a datestamp, in the form of S-62, or F-41 for eg, to indicate season and year. #Unlike for the guitars, there's very little info to be found on mandolin model numbers and specs. #Maybe your S-23 may actually read S-73? #I think that's about the last year Harmonies were made in the U.S.
"Listen louder, play softer"