I'm surprised to see a 1 1/4" tire rated at 100psi. My first 10 speed had 27 x 1 1/4" tires and they were rated for 70psi. Even when the fancy 1 1/8" tires came out, they were only rated for 90psi.

If those are the only markings on the tires, they are probably just the cheapest OEM tires that Univega could find .. or maybe they are cheap replacement tires?

They could be original, for sure. I've got the original tires for my '74 Raleigh International. A bit of light cracking on the tread, but they hold air. I wouldn't consider pumping them up to pressure, much less actually ride on them, though. If they were a nice set of silks... well, maybe then.

Steve in Peoria