New Pre Monobloc and Monobloc are available from Burlen and it's not because you've had a couple of bad experiences with probably old clapped out ones that all the new ones are crap. This year only I've fitted about 8 bikes with new Amals and not a complaint from my customers so far!The concentrics date from over ten years after the demise of Vincents they match with the dying products of british industry commandos triples etc not Vincents. indeed monoblocks only just scraped in and 'ugly' is in the eye of the beholder. For a matching number bike thats striving to be accurate a new 276 for riding and performance I would go for a Mikuni
I have no car or modern bike, my only means of transport are my old Brits, they are ALL ridden intensively, rain, snow or shine with Amals, no modern clutches, disc brakes, modern forks, etc.
Performances are just what they should be for old machines.
If I'd want modern performance and behavior I'd just purchase a modern vehicle.
Ok, in my eyes Miks are very, very uglies.