Yeah, those shifters suck ass. At the nonprofit bike shop if I see RapidFire (pre-RapidFire+) I pretty much assume both will be dead, but maybe one will work but really crappily. Sometimes spraying a bunch of WD40 in there will fix them but...

Once upon a time you could get Deore II thumbshifters for $20 a pair all day long and that was the ticket. But now you usually have to pay a bit more for those.

If you check the catalog link I posted I'm sure you could find which year was purple. You can also check the component codes off the cranks, for instance, at vintage Trek website, they have a good Shimano date code index.

Those bikes actually ride pretty well, IMO.