Bersa Thunder 380 a few years old?

I got, both my wife and daughter a Bersa Thunder 380 a few years ago right before they came out with the Threaded Barrel version. Of course, they had to change it with a Bigger OD Barrel so it's not easy to convert our older pistols. I stumbled a while back on some Threaded 9mm Barrel Blank Cutoffs 7.9 inch Long and 1 in 10. I forget the Barrel Thread, but it's not the common 1/2" - 28 Thread. My thinking is to turn these down to our Barrel OD. The 3D Model Barrel is 4.1". I found the other day a Recoil Spring upgrade using the Walther PP 18 lb Spring not the PPK, that reduces Recoil. The Girls want to put on a Compensator on theirs like below.

Question:
#1 Which way does the Barrel Retaining Pin come out?

#2 How do you make the Barrel Retaining Pin Groove in the New Barrel?

#3 Do you replace the Barrel Retaining Pin with a new one?

#4 Is there anyone offering this Threaded Barrel Service for these older Bersas?

Thanks for any Insights.

I have a Browning BDA 380 for me. Does anyone know of a Threaded Barrel option for it? I see Bersa has a New TPR Plus 14-shot model with a Threaded Barrel.