Nice condition 3 speed BSA gearbox for the 350cc SV and OHV L series from c1923 to late 1920s. Selects all gears, no broken teeth, kickstarter ratchet good - since listing I have found a top cover plate and screws - thought I had one somewhere! - and have added photos, so the only thing missing now is the kickstarter stop which is basically just a 5/16" cycle thread bolt with an extended head that hits the kick pedal when it reaches the top.
Postage is estimated - goes up so often it's hard to keep track of - but I post at cost and anything more than £1 over what it costs me will be refunded.