I had a lengthy discussion the other night with someone about what exactly “transitional” means when discussing 4001 basses. Based on that, I went to the photographic evidence on the register to try to kind of put a timeline to all the changes. Two things to bear in mind: there are ALWAYS exceptions to the rule when it comes to Rickenbacker, and the register is useful but not 100% reliable. That said, I think this is a pretty good timeline but welcome any corrections. So here is the complete transition from “vintage” 4001 to “modern” 4001. Please note that I don’t discuss tuners.
1968 December: bridge horseshoe pickup replaced with Higain
1969 April: pickguard shrinks; gap between bridge pickup and pickguard grows
1971 January: headstock shortened
1972 March/April: skunk stripe appears, headstock wings change to maple.
1972 December: tugbar disappears.
1973 March: crushed pearl inlays replaced with full width acrylic inlays
1973 April/May: full width acrylic inlays replaced with inset poured inlays.
1973 April/May: gap tooth bridge disappears
1973 August: checkered binding replaced with plain
1973 September: neck Toaster pickup replaced with Higain
1975 May/June: neck pickup moved 1/2” back from neck. FULLY TRANSITIONED