Ive got some wheel axles that have flats on them

think they were from old Raleighs
So they could use the thin slot drop outs with wheels that arent 3 speed.

Dont know if you can buy them now

a 27" wheel from a Raleigh will likely be Von Shothorst is that how its spelt.. or Rigida rim on a Maillard Atom hub.
The hub will be 36 hole maybe 32. And be more normal width. Too wide for the forks.
The axle will be 5 16th inch so that will fit.