Since the 3 or 4 speed shifter works, the only issue would be the cable ferrule. The older shifters have a threaded hole for a threaded ferrule and the later shifters (after 1963 or so) have a keyhole slot for ball end ferrules.
edit:
I may be wrong about this. I've never had a later 4 speed trigger. It may be that only the later style 3 speed triggers got the keyhole connection. Here's a late 60s or 70s 4 speed trigger and it still has the threaded hole.
70s 4 speed trigger
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Last edited by BigChief; 08-16-18 at 06:29 PM.