27x1-1/4 were very common into the early '80's. I just bought a new tube (Continental) from my LBS for my 1981 vintage 27x1-1/4 wheels, they showed me the box which listed the compatible sizes: 700C, 27x1-1/4, 1-1/8. etc. Mine are presta valves. Tires are harder to find, but not rare in most cases.