Thanks everybody! I didn't expect such a response, as Sprint was not around for long. To be clear it's the friction version that is OEM to the bike, so that's the plan.
Though I was thinking I could use a Sprint 9000 RD if it turned up and try to get the indexing to work. I have a pair of the Sprint 9000 shifters and probably a later Suntour freewheel.
Please PM me with specifics, $ and/or anything you're looking for.
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I never think I have hit hard, unless it rebounds.
- Dr Samuel Johnson