well, if it's of interest, I've been scanning the 57 accessory manual and translating to html -
bu light is RPO 987454 [no business cards added

] - I'll leave it there for awhile for anyone who wants to save it all to their puter [consists of 4 pages and 6 pics] - can't be much different from 30's to 60's . . . the light shown for the stepside fenders looks almost the same as front park light for 55-57, which is repro'd
Bill