Thanks Mark - I think you may be right as I had a few requests for 15 tooth front sprockets which must have been for Raids. 15-44 would be very high gearing so 15-48 sounds right.
I can't find Raid specs on the interweb and don't have access to an owners manual
The 15tooth 428 front sprocket is actually SMALLER than the 13tooth 520 sprocket - this causes one hell of a havoc when you "upgrade" to the 520 pitch set whilst trying to change the gearing - it gets awfully confusing!