Are you talking about an M9A1 or an 92A1? Look at Shipwreck's pictures for differences between the two--the easiest to see is the recontoured trigger guard. The M9A1 has the 92FS trigger guard with the flat front triggerguard while the 92A1 has a rounded triggerguard like the old, pre-92F Beretta pistols.
I'm not aware of any 92A1 pistols without the integral ergal recoil buffer, and no 92FS pistols have an integral recoil buffer of any type, so I'm not sure what you mean when you say that the recoil buffer in the pistol you stripped was the same as the recoil buffer in a 92FS.
As far as the recoil spring goes--I suppose someone could have changed out the captive recoil spring assembly for a standard 92FS/M9 type recoil spring guide and spring.