Having read the entire thread, here's what I'd suggest:

1. Since the OP doesn't quite feel the need for a triple chainring (which seems to be the standard on most bikes nowadays), the Redline Metro 9 (1x9) might be an option.
2. OP is now on the fence about disc brakes and is open to the idea of restoring current Klein.
3. Get the Redline for the daily driver AND turn the Klein into a project bike.

End result? Two bikes and a skill set/knowledge base to keep both running.