Please post images of every mark on the action and barrel flats of the W. Richards. "London Fine Twist" usually implies a Belgian maker.
Feb 24, 1900
Sporting Life The Winchester people offer the Repeater in 10, 12, 16 and 20 gauges, loaded with any of the standard brand of Nitro powders; the maximum loads for this shell being
10-gauge, 3 1/2 drams powder, 1 1/4 oz. shot (shell boxes list 28 grains Ballistite or Laflin & Rand Bulk Powder).
Until the 1920s, the heaviest North American factory loaded 10 gauge shells offered were 1 1/4 ounces of shot with 4 1/4 Dr. Eq. of smokeless powder in a 2 7/8 inch case.
There is quite a bit of information on the PGCA site regarding the "Short 10"
http://parkerguns.org/forums/forumdisplay.php?f=21 
