I have 117X T, T for twist, which I figure is just a year or so older than yours. Mine has been abused more than I like by someone who pretended to be a gunsmith. It does have rather nice engraving much like the art deco style, like Ithaca and Smith used in later guns. Sometimes you can find a grade stamped on the water-table, like 32 or 52 along with D for Damascus or T for twist. Pictures always help.
As to value I think this is at the upper limit for the basic Aubrey unless in very, very nice condition. But if you like it buy it anyways. Solid shooters are worth $500 in my book. Or I rather not shoot many guns that are not worth that much. You will look a long time to find them in high condition as they were mostly used hard and put up wet.
