Can anyone identify the rear hub standard in the picture below? It's from a Raleigh Sport, with black concave rims. I've been given the bike to do up, but the lock ring for the freewheel is missing. Hopefully with a name I can search out a replacement.
Any help greatly received!
IMAG0542 by nathangabbott, on Flickr
Nathan
Any help greatly received!

IMAG0542 by nathangabbott, on Flickr
Nathan