Okay, got my Best copy now. Using his comprehensive catalog section by serial range, we can now be even more precise:
I’ll assume the grip panels are original; they are the only obvious difference between the civilian New Army and Navy versions. The serials ran concurrently.
This is a Civilian New Army Model of of 1894. This iteration was made from mid-1904 to late 1905 between 222xxx and 254xxx. So one can extrapolate this 243867 into the first half of 1905. It should have the reduced-diameter barrel for .38 Special, as that started in the first quarter of 1904. But the barrel marking did not change from earlier and still just says COLT D.A. 38.
As for buying it, maybe talk the guy down to a Franklin using all the doom and gloom arguments here, but then buy it for the education. It’s not a collectible, but for that price, you can learn all about them and maybe later find an all-original military model.
As for the mechanics, I don’t do internals, but in talking to people who do, my impression has been that they are on the more complex side, but still just a mechanical device that can be fixed, and the difficulties of repair have become “conventional wisdom” and grown as it gets passed on. You may indeed need a gunsmith who can do more than field-strip a Glock
This model and its variants deserve more attention for their historical importance. They suffer a lot from the caliber being bad-mouthed as part of the .45’s creation myth.