Pistol out and round ball in?

I have a 1970 Duster 340 factory 4 speed. The 2nd owner put a pistol grip shifter (and mechanism?...don't know) from a '70 Superbee in it around 1973. It is the "slip-in"(bayonet) style handle.

Can I just install a "slip-in" style round handle with ball in to the same mechanism?

Need pointers on getting the pistol handle out. I know it involves a feeler gauge.

Thanks for the help!