I have an older FNP9 that has the silver barrel, decocker, mag release, etc. I just purchased another one that has the lightened slide and updated decocker. I was wondering if I could send the gun in and have the new decocker installed since it is sooo much easier to operate. I would like to purchase a new slide also since the new gun feels much lighter than the old one. And lastly, my old mags have plain colored springs in them verses red springs in my new mags. I've noticed the old mags barely push the slide release up just enough to catch the slide where the new ones push it all the way up in the groove. Has anyone ever upgraded?