Antique White Treadle Sewing Machine

I have a 4-H member who is restoring a "White" treadle sewing machine which was her g-g-grandmothers. It has 2 drawers on each side and a simple front piece. Had to take apart to work on it and I don't know if I deleted photos of the original, looked high and low, but cannot find them. We can't figure how it goes back together.
Anyway have the serial number either 1312644 or 1512644. Hard to decipher the 3 from the 5. On top of the machine is placket: "registered in
U.S. Patent Office" It has a long round shuttle. The pressure foot is secured by a round nut type that turns like a nut on a bolt. On the front plate covering the shuttle: "White S.M. Co. Cleveland OH". On the back plate behind the needle is a list of patents:
USP 76, then 8 patent dates: Mar. 20, 1877, Mar. 27, 1877, Jul 27, 1882, Ap 24 1883, Jul 15, 1884, Dec. 30, 1884, Dec 4, 1888 and May 21, 1889 then 3 the same date of Mar 11, 1890. Assuming it has to be made after 1890.
Cannot locate a source that gives that far back for serial number, so would like to know when it was manufactured.
Lorna Grow