Having resurrected this Ron Cooper several long months ago I finally got it back on the road again this morning after a recent stem, handlebar and brake lever/caliper reshuffle. Five good hours with no ill effects beyond the pleasant tiredness that comes with such escapades. Next steps probably a different saddle to facilitate a more stretched out position (the Selle Anatomica here sits fairly forward and is quite triangular) and a 28t large sprocket (many thanks again
pastorbobnlnh !) to defuse the 53/39 effect a little…