Sorry I missed your post until now. Art is the most experienced on this forum and maybe anywhere else. He mentioned the AMX but he may have meant the AMS... not sure about that. I know the AMS people have two different 3-piece devices: The LGX and the CX. The CX seems to be better with regidity of erection and girth and the LGX seems to do better on the length. At least that is what I have deducted through my months of expeience with the implant. So find out which device you have.
One indication that there is a mis-size is a floppiness with the head of the penis when pumped up. It sounds as if you may...may have been mis-sized. The LGX actually expands up into the head of the penis whereas the CX does not.
Most guys receiving the implant notice some shortening of length and girth. I did not expeience shortening of the girth but did experience a shortening of the length...anywhere from 3/4 of an inch to an inch.
As to the cost of a re-do, you may... may have a case for a re-do. But I would not know for sure about that.
Since you are "Texdoc48" I suspect you live somewhere in Texas. I live in Dallas. If you want to talk, email me (available at side-bar) and I'll email you my contact information.