There are prop replicas being produced by many companies,who out source to China,that are many times more expensive in comparison to what ADI was offering.
The paintwork on the A3 maquette is faithful to the original paintwork.ADI didn't make or paint the puppets.They made the clay sculpt (sculpted by Chris Cunningham/Halls) that was used to make the molds.ADI was very busy at the time working on all kinds of props for the film,so the puppet work was handed off to Boss Film.An artist at Boss Film painted the puppets after they where made and used the paint master maquette that ADI sent,which was painted by Gino Acevedo,as a reference to work off of.
ADI had to purchase the liscense from Fox to make these pieces.ADI owns,and still owns,the original A3 maquette/puppet molds.Anything that comes out of those molds is still Fox/Disney's IP.
On the subject of the teeth. Yes,the teeth are not the same.I mentioned before that they are completely different between the puppet/ADI maquettes and the suit heads.