Got a '65 Mustang 4 speed shift knob I am trying to put on a '57 T-Bird shift handle that I have welded to the Hurst shifter on a toploader 4 speedI am putting in my Bird. I modified it so it comes through the stock chrome shift tower on the T Bird. Want to use the Mustang knob to avoid confusion if anyone else ever drives the car. Mustang has 1/2" fine thread hole and  Bird handle is 3/8" fine thread. Need a bushing with 1/2" fine threads on the outside and 3/8" fine threads on the inside. Local hardware has a ton of neat hardware but not this. Any ideas where to find something like this?