B-Square scope mount for a Ruger Single Six 51/2"barrel

I am looking for a scope mount base for a Ruger new model single six .22 pistol with a 5 1/2" barrel. I have seen pictures of these on the internet but cannot find one for sale anywhere. I would prefer a stainless finish (silver) but a blued finish will be fine as long as it fits the 5 1/2" barrel. I've checked with B-square's site and they no longer offer that size since Ruger no longer makes the 5 1/2" barrel. I would greatly appreciate anyone who is willing to sell me one of these. Thanks