For what it's worth, the problem is resolved. I was incorrect about the necessary spacing of the axle cones: the axle that worked out was of almost identical dimension, but the cone was forged infinitesmally thicker, and was an unknown part. It also wasn't hardchromed, as I'm guessing the Raleigh part was. The cups I found with this axle were threaded a bit deeper, and had a hex forged into them for tightening, unlike Raleigh's tapping flats.

Neal, many thanks for giving me "ground zero".

Al