The bike is a 1996 Cannondale 2.8 R500 with 3x8 (26/36/46), just bought cheaply knowing it had "shifter issues."
Jim McVey has the shifters and will be restoring their functionality.
Another issue is the not-original Suntour generic front derailleur - it's a no-go since the cage hits the chainstay when the derailleur is mounted down near the chainring where it's supposed to be.
I'm searching eBay etc. for a 31.8mm RSX A410 front derailleur - what other ones will work? (Low cost solution preferred, this will be an interim ride for my tweener son, and then either sold whole or parts moved to a larger frame than the 52 I have. This bike has maybe 200 miles on it as far as I can tell).