I severely doubt it.
There is a RGM Honda lever, but I doubt any of the adjustable lever makers would have an application for that.
JAPANESE MADE ALUMINIUM BRAKE LEVER WITH PROTECTIVE CLEAR PLASTIC SLEEVE AND BLACK RUBBER BALL END TO SUIT OUR UNIVERSAL FRONT MASTER CYLINDER PART NUMBER
www.rgmnorton.co.uk
Maybe some one like
Pazzo (Vancouver, BC) would do a one off if you sent them 10x stock clutch/brake levers and they could match their existing lever (short or long) and cam mechanism to a machined down base of our stock levers. I dont know if they would even entertain it or if it would be cost effective.
View attachment 95843
Another option would be to find someone in our community here with the machine skills to do that using a standard cheaper adjustable donor levers, and using new stock Norton levers provided by customers as a core.
You wouldnt need to fully machine the pivot block and hole as above, just the interface for the cam/handle.
When I crashed my Norton last year and broke my shoulder, it rashed up the clutch lever. I got a new one from Pazzo and they sent me the wrong pivot block. All I did was swap the lever part to my existing pivot block, which was fine.
Either of these options would likely to need a group buy to be feasible.