I had a run of alloy B50MX fenders made, front and rear. Stainless are difficult to source so I went with alloy reproductions. They are the same shape and bend as original save that the alloy fronts seem to be shy of just about 1" in total length if compared to an original. Makes no difference in appearance once mounted. As with all the reproduction B50MX high fenders none come with the reinforcement strip along the middle underside like the originals did. It would be prudent to use a good size fender washer curved to fit to support the mounting bolts, front and rear. These fenders have the rolled edges all around and the fronts have the proper end flares.
The alloy fenders weigh half of what stainless fenders weigh. I wonder why BSA didn't go this route with the B50MX? Alloy seemed to be the choice of the B44GP fenders and saves a couple pounds.
I also had a short run of the 1972 B50T / 1973-74 TR5T high chrome fenders made up.
While I was at it I had a bunch of B44 rear chrome fenders made up as I was down to my last few, or I should say foresaw that by the time the fenders would be made I'd be down to my last ones. These are the correct B44 bend with the cutouts for the fender and exhaust pipe.
All of these were made by Autocycle Engineering in the UK who turn out better BSA fenders than most other do.
So a partial list of the new fenders I have available:

B50MX alloy fender set

97-4072ALLY B50MX HIGH FRONT FENDER - ALLOY $ 90.00

83-2934ALLY B50MX REAR FENDER - ALLOY $ 135.00

97-4333 B50T & TR5T HIGH FRONT FENDER - CHROME $ 180.00

40-6815 B44 REAR FENDER - CHROME $ 225.00

41-6533 B44 VICTOR FRONT FENDER - CHROME $ 190.00
Pictures of all of these are also on my website: http://www.bsaunitsingles.com
I'm hoping that these will be of interest to folks.
Peter Quick
BSA Unit Singles LLC