Elation to depression in five minutes

Replacement fifth gear cogs for my Guzzi Quota arrived today. Yay.

One is entirely the wrong gear, though. Boo. Looks like it's one of
the lower gears off a 750 (it's straight cut, not helical).

Worse, the wrong gear supplied would have replaced the most worn of
the two. Worse yet, I don't think Guzzi make them any more: the gear
was old stock the dealer had lying around. I might have to resort to
either buying a second-hand gearbox, or maybe fitting a 750's top gear
set, if the ratio's close enough.

Arse. So I won't be rebuilding the Quota's gearbox this weekend after
all. I'll be popping out in a few minutes to buy a few bottles of
sorrow solvent.