1860 Colt Army 4 Screw Question.

I've read that there were over 200,000 1860 Armys made for the Civil War, so that serial number would seem to be well within range.

Considering that the serial numbers were hand-stamped, maybe the guy doing the stamping had just gotten a new '8'?

There were only 156,000 1860 Armies made through the end of 1865, a little more than 127,000 being bought by the Federals. The 200,500 number is total production through the end of 1873.

Don't know why the 8 was added - and it definitely looks like it was.. Could have been a factory rebuild??? I'd be curious about what SN is on the arbor, backstrap and grips. At any rate, the cylinder is not original to the rest of the gun with the 7744 SN stamped on it.

I have an original 1860 and the serial# is centred on the bottom of the barrel where it meets the frame as well it is centred on the frame and the trigger guard. On your example the serial is centred on the barrel where it meets the frame as well as on the frame, The serial on the trigger guard is off centre and it looks like they made the last number (8) a very light strike so that it is not as obvious that they made a mistake. Notice also that the spacing between the numbers is very tight in order to make up for lost space. I suspect that the serial number has not been altered and if you can get pictures of the numbers on the back-strap the wedge and the arbor that would help.
On my gun there is no room to add a number to the serial (last four digits) on the arbor so if there is an 8 on the end of your number that should prove that no number was added.
The cylinder as noted has had the number stamped in a space where it shouldn't be and so is probably not original to the gun.
The fourth screw could have been added in order to mount a stock onto the gun but you are right in that they stopped adding the fourth screw early in the production.

The 8 could have been added to ''force match'' the numbers...

Looks correct to me for the way they did it then.