27 x 1 1/4 inch tyres (Raleigh Stratos)

If you Goggle "non-hook rims" there's plenty of info.

In short, early non-tubular rims didn't have the "hook" on either side of the rim, into which the bead of the tyre fits: see the pic above. Hence them now being referred to as "hookless".

I'm wasn't aware that there were ever specific tyres for hookless rims; either way I've never seen any for sale. However, modern tyres with a bead can be used on hookless rims. Ignore what is on the side of the tyre and run them at no more than 75psi.

It's generally recommended to use tyres with a wire bead (ie not kevlar bead, folding tyres) and I've seen using two layers of rim tape suggested. I've not found extra tape necessary and be aware that it will make it harder to fit your tyres.

There isn't a great deal of choice in 27":

• Panaracer Pasela - probably the nicest ride and best all-rounder;
  
• Schwalbe Marathon - as close to puncture-proof as it gets and very durable;
  
• Continental Gatorskin - doesn't ride as nice as the Pasela, not as puncture proof as the Marathon, reportedly sketchy in the wet, but pretty durable;
  
• Michelin World Tour - very cheap, which is likely all they have to recommend them.
  
  

If you get stuck, I have a pair of Marathon I don't need.