Switch pool cue butts but keeping my shafts - 5/16x14

I have a falcon pool cue butt. I like the pool cue butt but it is not ideal. I would like to look for a new butt. I have a schon shaft, a falcon shaft, and a diveney shaft that I would like to use with a pool cue butt that I like better. They are 5/16x14 steel shaft. I know that I had to have some work done to make the schon shaft (it was originally a 5/16x14 too) to fit the falcon butt. How do I find a butt that will fit these shafts? (obvious answer one that fit 5/16x14 but I wanna make sure that I don't waste my money)

Thank you!