I have never heard of anyone being able to get anything but entire mags or, if ordered from Kel-Tec, mag springs.

individual components for the MecGar mags are not available.  Neither KelTec or Mecgar will sell them as pieces.  Mecgar ships KelTec completed magazine assemblies from the plant in Italy.  I have contacted both KelTec and MecGar about this.

I'm not an expert, but I do own a P-11, and both 5906 and 6906 S&W pistols, and a bunch of 17 rd MecGar S&W mags.  Been doing a lot of research on mags, interchanging, modifying, sleeves to make the long ones fit, that sort of thing.  I just wish I could find a HIGH QUALITY aftermarket 32 rd S&W magazine, for my P-11 of course.  I figure all that mass hanging down should dampen muzzle rise...........