Peter, I've a spare pair of bonnets from my 4/4 which I tried on Nero.....neros bonnets are a pretty crap fit...but they were well out. The bonnets certainly are bespoke.
On my 4/4 I looked at having the factory weld on an SS scoop to the existing bonnet but wanted the old style side louvres which the SS and Baby Doll have. Expensive as that meant a pair of bonnets at about £1400 painted and fitted!
They did accidentally make a scooped bonnet with the modern side louvres which I declined and that's now on the Williams race 4/4! It looks good...I should have gone for it and saved myself some money!


Jays
Former Morgan owner. Gone but hopefully not forgotten!