I've got 2 hand made alloy tanks on a couple of my Ducati's and they were made by Terry Baker later to become known as TAB in Wales.
I'd put their quality up as least as good as the mega priced Japanese kit (if not even better!) and they aren't that expensive.
Here's a link to their excellent (IMHO) work:-
http://tabclassics.com/
The Imola alloy tank on my '79 900SS has been on there for getting on for 40 years now, it's only needed one repair in all those years (covering well over 100,000 miles) and that was because the replacement alloy silent blocks supplied by a specialist were too stiff!
I can't say any fairer than that.😁
Steve R