For photos, click on the links below:

1971 4001-S features: Cresting wave shaped headstock with walnut wings, Grover Imperial non-wavy tuners, logo on plexiglass truss rod cover, full width maple neck through body design, dot fret markers, 20 frets, no binding, toaster shaped neck pickup, four pole bridge pickup including cover and chrome surround, white pickguard, clear plexiglass thumb rest, black heptagonal shaped knobs, CTS potentiometers, Sprague "orange drop" capacitors, cloth wiring on pots, pots cavity marking, 3 way pickup toggle switch, chrome "gaptooth" bridge assembly including mutes, mono input jack plate.

The letters on the chrome input jack plate determine the year and month of production. The digits indicate the number of production. Some examples of 1971 Rickenbacker serial numbers are:

KA xxx 1971 January
KB 06x 1971 February
KC 45x 1971 March
KD 18x 1971 April
KE xxx 1971 May
KF 52x 1971 June
KG 44x 1971 July
KH 87x 1971 August
KI xxx 1971 September
KJ xxx 1971 October
KK xxx 1971 November
KL xxx 1971 December