ef37a wrote:Son has had a 330 (360, can never remember*)
It was a 330.
(230s are real dentist guitars).
The Rickenbacker guitar necks are already on the narrow side, and the 12-string necks (I believe) are the same width as the 6-string ones. 12-strings normally have wider necks to keep almost the same string spacing between adjacent pairs as between strings on a 6-string, so trying to fit 12 strings into the same space as 6 strings doesn't leave much of a gap.
I had the same problem with a Yamaha Pacifica 12-string electric. Strings were far to close together to play easily, so I gave it to a mate with smaller fingers.