Hi Cas, I would say your front brake lever and mount are Norton 16H, looks just like the one on my Norton.
Getting lever fever is a bad illness and can take a long time to cure and it's not cheap unless you're lucky
Just returned from Wuxi in China today and the first of two packages was sitting there with four sets of NOS levers. When I receive the rest I will contact all parties whom requested some. They are covered in thick grease but I will leave them for the new owners to clean up.
AAHHHH, I must be drunk Amazing find, I would be in the queue if I hadn't a spare set.
These levers work great, especially the valve lifter, much and much better than that stupid little thumb lever that pricks into the tank.