I have a little spare time, and am looking into this. The easiest way is just to weld an extension on the original.. I think that's what Phil did.
If there's enough interest, I'll make a form tool and new levers out of 4130 with the 12mm extension on the CNC mill.
How much would I have to charge? Dunno. I guess it depends on how many I make, but it Shirley wouldn't be over $50.
Reply here or send an email to 59.Chuck Gmail.com
2016-08-24_03-08-08 by Charles Stottlemyer, on Flickr