My LCP like my P3AT also has a plastic mag catch. It is one of the first produced which also came with the stainless steel barrel. The post-recall LCPs come with a blued barrel and a metal mag catch. Unlike KT which will give you any "upgrades" for free, Ruger wants $8.50 for the new metal mag catch. I pled with the Ruger CS that they should send me the metal upgrade but compant policy is, if you want the upgrade, you gotta pay for it! >
A look at an exploded view of both guns shows that the mag catches (like the rest of the dang guns!) are identical. It is highly likely that with a little fitting, the new Ruger metal mag catch will most likely fit the P3AT perfectly.
The P11, P3AT, and P32 have been in production for years longer than the PF-9. I admit that I just don't understand why they went to the metal mag catch in the PF-9 but not in the rest of their handguns. I would think that a switch would have already been made. Apparently, their our not as many failures of these plastic mag catches as many people think there are.