Back then, late '60's, I was riding Dunlop road racing wired on clinchers. They were rated at 75 psi, but would always take 90. I'm not sure that they were 1-1/8" or 1-1/4". Even as a teenager, I was hoarding them at the time.
Dan Artley Parkton, Maryland
Steve Kurt Peoria, IL (rode my '71 Raleigh International fixed gear 40 miles after work today. When it was new, the best clinchers were 70 psi and 1 1/4", iirc)