Rivolier Pere et Fils was a bicycle and arms manufacturer located in St. Etienne since around 1830. As you have noted, information is pretty sparse on these fairly obscure guns. Apparently, most were built between 1928 and 1940, but the last shotguns were built around 1973. The company stopped manufacturing bicycles in 1950.
Assuming the date of 1973 is accurate for last production of shotguns, the one you have here looks like a virtually unused closet queen, or one that has been nicely refinished. The very light color of the wood is common to French Walnut... which is actually English Walnut grown in France.
You can disregard the information given by Gladys Kravitz, I mean old colonel. The Rivolier family reorganized the company in the early 1970's, and is now a French Defense Contractor that also is a retailer of hunting, fishing, optics, and outdoor goods.
