John, MT - thanks for the continous support. This was a big job, especially for Moggie noobs (and without welding experience - last time I did a big job was on a VW split window van, 20-odd years ago) like us. Mentally, it was a pig. Just to get to the point where the cutting out starts...all the ifs and butts that need to be sorted, and the tools of course.
But - once overcome, the rest looks doable. Ah, yes. Paint. Good question, John. I haven´t seen cellulose paint used or sold in Sweden since about 1976, except for spray cans in guitar shops, and then mostly as clear laquer. I used to be a car painter and have done a few old Mercs, Volvos and Fords and the odd horse cart in cellulose, but all that disappeared within the more common and widespread use of synthetic and later 2-K paint.
Now, I might be mistaken, but I believe EU rules out anything non-water-based as of this year, making it even harder to find usable (DIY) paint. I need to check with the Morris parts guy in Gothenburg. I´d love to do a cellulose job on Betty, provided she´s not (re)sprayed in synthetic to begin with (which I strongly suspect).
In any case, that´s academic at this point. We are only looking to paint the engine bay so we can put the engine & gearbox back into Betty ASAP.
And the engine bay will not be Smoke grey, but something either matching/close enough or a nice contrasty color like a slightly darker grey.
And we will probably use some enamel/laquer from the farming world. Durable stuff (IME), gas & heat resistant, good-looking even when brushed on - and cheap. And it can be applied in cold weather

- watch this space for preliminary results this weekend.
Edit:
update: due to unforeseen (but anticipated anyway) rot discoveries needing immediate attention, the painting of the engine bay is re-scheduled to the coming weekend.
Cheers /Richard