My Shifter knobs are one of my best sellers and I am nearing the 600 knobs mark of sales with these. you will see many of them on the road in Hot Rods and Customs all over the world. I Collect vintage coins and I use bakelite shifter knob to create different and unique shift knobs for the last 10 years. Remember if you didn't buy it from me I didn't make it. 
 
Shifter knobs have a 3/8-24 fine thread and I have a 5/16-24 early ford insert for them. I always tell folks if you want to run it there are many ways to get there for mounting. See mounting tips
 
Mounting tips-
Just some ideas, if you really want it on your car you will find a way.
Re drill and tap
JB Weld
Cut a 3/8 bolt and weld it to your shifter arm
weld end of your shifter and clean it and tap new thread
Lokar has a lock out kit to run other knobs (website)