The original Dawes cog set was five speed/14-28, as I recall. Non-indexed, of course. I can't recall the most commonly used freewheel, but Atom comes to mind...



The rim of choice, in steel was the 27" Rigida patterned braking surface. Again, this is based on recollection, not etched in stone fact. To be sure, just check the original front rim of the OP's bike. That should be definite rim make/model information to work from...