I wish you luck in connecting with the Merit Sight Company. At one time they were the go to place for specialized sighting equipment and had some well known and popular products. Then they kind of disappeared for many years. They made a bit of a come-back, but only with a couple of items, not at all like they once had. They used to sell their products thru Brownell's, Midway and E.A. Brown Company. The Brown Company carried a lot of Merit items as well as others.
None of the usual suspects has anything Merit related today including E.A. Brown. I called E.A. Brown several years ago looking for a rubber ring for a Merit Disc and was more or less told they could not obtain anything from Merit and they removed all reference to Merit products form their website.
The last items I saw available from Merit was their suction cup eyeglass lens attachment and one single model of their adjustable aperture rear sight which I think was designed for hunting use only. It did not have the rubber ring around the housing. I was a little late to the party looking for some of these items as there was, at one time, a great many sources for specialized sights and optical aids, but they are long gone now. Millett sights was another great source for iron sight products, but they no longer make anything in that regard. Trying to track down specific items or parts for these long discontinued products can be lengthy, but persistence can pay off. I did eventually find the Merit aperture I was looking for, but at twice the retail price via Fleabay. Gotta pay to play I guess.
Rick H.