Balder, at first glance it does appear it is an AE model. Placing a marking on top of the chamber was something that DWM did as a marketing tool, so you will find Bulgarian, Russian, Swiss, etc., markings on the chambers of guns sent to their country under contract or for sale.
There were test guns made for the US in testing the Luger for possible adoption as the new pistol, but your's at serial number 73xx is just out of the range by several hundred.
Relining is an option and would preserve more value than re-barreling. Both wil dimish the value, although if it has been "drilled", much collector value has been lost.
There are lots of threads on American Eagles and you can do a search both on the Old Board and the new board and re-read many discussions.
Can you tell us any other markings on the gun?
Proofs? (see on your left under tech information if you came through
www.lugerforum.com) Tell us what and where proofs and markings are located.
There are forms in this section, where you can print out and then write down pertinent information.
What serial number is on the gun? To include any letters next to or under the serial number?
What year or letters are stamped on the top of the receiver?
What initials or letters are on the toggle?
Can you provide pictures, to include side, top, etc?