I found 2 wheels, which appear to be 700s. There are no markings on them other than the maker (an Italian one) and the hubs have Normandy marked on them. They seem to be made of aluminum.
Is there any way to tell what size tube and tire I should use? I have finished cleaning and packing the hubs, but couldn't get a 700x38 tire on. I wasn't sure if it was just my poor tire mounting technique or something else. What can I measure to accurately determine the size.

Thanks for the help. As you can tell I am a little new to this, but really love finding old bikes and parts and fixing them up.

Iceman

Try a 27 x 1 1/4 tire on them.

What he said^^^

I found some wheels with brand new tyres on them, beauty, methinks, I'll put these on my old hybrid with 700C wheels, but when I pumped them, the tyres came off the rim. Inspection showed them to 27" tyres.

The 27 1 1/4 worked perfectly. I didn't think to try them cos I figured all alloy wheels are 700 (being newer).

There was a really long overlap between the time when alloy rims were used even on cheap bikes, and the popularity of the 27" tire size in the U.S. I regularly find 27" alloy wheelsets in trash heaps, mostly while walking my dog.