You have the early version of the engine. Here's a link to one sites take on the Lionel 1130.
The re-stamping of boxes is not too unusual.
No set number on the set box? It should have one.* List the cars, transformer, track, and any accessories and someone may find you leads for a more exacting answer.
* I don't know how prevalent it was, Lionel was local, and it was the highest grossing store in the country for years, but a Sears near here would assemble or swap cars for Lionel sets readily. Usually the paperwork reflected it. If there was a need for a bigger box, there was a "different" Lionel set box (A Lenny box) supplied to them by Lionel and Lionel/mpc; as well as a Lionel rep. and repairman there on certain days. He gaurded the use of those boxes well, stamped them himself all too. But I managed to con one from him eventually with no # markings when my X set's box got soaked and died in a flood. 
