Bob, I think Greg has it pretty much right, I have or have had 6 Robust over the last 3 years. My thinking is that the 22 on your gun is the grade marking, it should be repeated on the front edge of the barrel flats or on the lower rib in front of the flats. I read somewhere that the grade numbers changed in the 1920s from 1 number to 2 numbers, about 1929 they went to 3 numbers but the middle number had nothing to do with the grade. Go figure must be a French thing, the following is a recap of the Robusts I have and the marking
1. #41992, marked 4 on the front lug and the barrel flat, no grade marking under the top lever, just the serial. Front lug extends through the action, no rib extension. Straight grip, 16ga, non-ejector, moderate engraving. Forend is like the one you pictured
2. #42907, marked 7 on the front lug and the barrel flat, no grade marking under the top lever, just the serial. Front lug extends through the action, has rib extension with top fastener. Straight grip, 16ga, non-ejector, quite bit of engraving. Forend is the odd one we discussed before, HRBP w/Manufrance logo. Has retractable sling.
3. #84623, marked 20 on the barrel flat, 20 marked under the top lever under the serial. Front lug does not extend through the action, no rib extension. Straight grip, 16ga, non-ejector, no engraving. No Forend , but must have been like the one you pictured, steel buttplate.
4. #137763, marked 214 on the lower rib in front of barrel flat, 214 marked under the top lever under the serial. 214 and 24 marked on plate in front of the triggers. Front lug does not extend through the action, rib extension with top fastener. Half pistol grip, 16ga, non-ejector, moderate engraving similar to the one marked 4 .Forend is secured by a roller and spring, steel buttplate. Date of 29 Dec 1929 is stamped under the buttplate in green ink.
5. #144689, marked 216 on the lower rib in front of barrel flat, 216 marked under the top lever under the serial. 216 and 26 marked on plate in front of the triggers. Front lug does not extend through the action, rib extension with top fastener. Straight grip, 16ga, non-ejector, more engraving than the one marked 4 .Forend is secured by a roller and spring, HRBP buttplate with Manufrance logo, stock has been shortened slightly, has retractable sling.
6. #166216, marked 201 on the lower rib in front of barrel flat, 201 marked under the top lever under the serial. No marking on plate in front of the triggers. Front lug does not extend through the action, no rib extension. Straight grip, 16ga, non-ejector, no engraving .Forend is secured by a roller and spring, steel buttplate , has the date stamped under buttplate 5 Feb 1932 like 214.
The forend irons on 4.5.and 6 are different than the others, they have a curved extension where it joins the wood .
Digital photos are a trial and error; I think lighting and a tripod help the most. Flashes seem to produce glare and over exposure unless you have an expensive setup. I made a light box with some PVC pipe, a white sheet and some daylight fluorescent bulbs and swinging arm lamps. I have an Olympus SLR with a dedicated Macro lens, but my wives point and shoot will do almost as well. I bracket all my shots on auto bracket and pick the best one. Some times you have to tweak the image with a photo-editing program, I use the one that comes with windows
