I also have a 629 Powerport and can't recall if it was truly "Magnaported", which would surprise me because Magnaport is proprietary porting that usually resembles small ovals or trapezoids that are EDM'd into the front of the barrel that do not add any length to the original barrel. I always believed this was factory ported but don't have the spec sheet to be sure.
S&W actually did use actual Magnaporting on many guns that were PC limited runs.
Funny though that I had the Powerported gun below customized by Magnaport International with triggerjob and finish, but no Magnaports since it already had porting.
Powerport on 629
Magnaports on my PC Hunter