It is definitely an ASM just by looking at the rear shoulders of the trigger guard and the load lever pivot area. It also has the short frame, the short forcing cone, and the shallow V-notch load aperture on the barrel lug from the 1848 Pocket. It has the round trigger guard of the 1849.
The 1849 had a longer frame, longer forcing cone, and a larger beveled load aperture.
Historically, Colt only produced the 1848 for one year, followed by the 1849. As Colt never wasted a part, so the story goes, some late production 1848 pistols had round trigger guards, and some early production 1849 pistols had squareback trigger guards.
It appears that ASM was not picky, either.
Replica Arms ASM 1848 Pocket (XIX/1963) 6" barrel that I used to own. I have looong fingers and it got lost in my hand.
So, in actuality you have an 1848 with a round trigger guard. You scored very well.
You had better polish up that brass real purty for your young lady!
Regards,
Jim