I have a 9mm P239 SAS Gen2 with a rolled FPRP, it looks just like the pins in my older folded slide Sigs. But most of the P239 pictures I see on line and in this forum appear to be a solid pins. I used to be under the impression that the solid pin was used with all stainless slide P series. What do you think? Thanks...

The solid pin was used in the early milled slide SIGs. SIG later changed to the single rolled pin (aka spiral pin), which is not the same as what was used in the folded slide guns. Folded slide SIGs use two separate rolled pins (inner and outer).

Good info, thanks!