Reductions. The Paul brake is a Crosstop 3 I believe. Looks like a v brake but works with a canti brake lever (no brake hanger needed). Bikepro says the idea was based on the IRD widget.
Updated with the RF Turbine LP crankset in really nice condition. Hardly used, if ridden at all. Not sure if these are an unusual version, but there’s no milled-out section on the upper and lower arms. Serial number 0530, more pics upon request.
RF are a more lemon yellow than in the pics. Chainring bolts easy to find btw, 18mm if memory serves me, and the 8mm spacers are available from Tom AKA Synlos.