I have a Raleigh Grand Prix, fitted with the original Sturmey Archer 27 x 1.25" wheels. The tyres on it were fitted when I bought the bike about seven years ago. The tyres are Kenda, with a size of 27 x 1.25". I don't use the bike a lot and not at all in wet weather. I have no complaints about the tyres and have never had a puncture. It amazes me to be able to write that although I am now, of course, tempting Providence.
I do have a general question, in anticipation of when I need to buy new tyres: namely, it seems from several posts that 700c tyres can be fitted to 27" rims. Is that correct?