I have a breast Plate pre English Cival War.On the collar AT is stamped and on the right hand side if you had it on there is a small shield about 1/4 inch with the cross of st, George in the centre.Anybody any one with information on the maker or is there any books that could shed some light on the markings.I am willing to email photo,s............many thanks Mick Taylor The Northeast of England.

Mick, I think folks will better be able to help you out if you can post some pics here of both the breast plate and the two stamps you've mentioned.