what is the diffrence in the goverment 1911a1 and the thompson auto ordinance 1911a1.I cant see the diffrence looking at photos?

Without the benefit of seeing the pictures you are referring to, I would say, since both are 1911A1 barrels, that outside of quality of finish and slight dimensional differences that may require a little fitting, there shouldn't be anything that would preclude the use of one with the other.

The Auto Ordnance 1911A1 is just a copy of the Government Model 1911A1 ... no significant difference.

The AO 1911A1 is not a particularly good one from the standpoint of close tolerances or fine finish. It's what one might call "serviceable."