Jeff
I had exactly the same issue - I think they get caught on your trouser pockets when you get out of the seat.
All I did was got the threaded top knob (plastic) from one of the dealers and matched the thread of a bolt to it. It may have been 5mm or so. Then it was simply carefully cut off the head, weld the bolt on and grind the weld to the profile of the lever.
The knob has a 'sleeve' section before the thread started which easily covered the weld. Looked as good as new when done, and super easy. I didn't even need to re chrome!
Richard