Or like the AB868 with the vibrato ch removed

Another thing that has remained from the original. That manurey/goaty /
caproic acid smell that emerges when Fender (and other USA-made) amps are
opened to the air in the UK. No one else has come up with another
explanation - so I will stay with the US-patented use of fatty acids from
abattoir sources as a part of the formulation of the insulation of
transformer magnet wire. Then some reaction to UK humidity or UK-specific
microbial action. Not an unpleasant smell , just agricultural, not what you
expect to come from electronic kit.
This amp has a UK made mains transformer replacement so the smell , if from
inside the transformers then from the choke or the output Tx . I
deliberately kept the cab in another room this time , no smell there, so not
horse glue used in the cab making.