I think the one piece mount is probably for the red dot type sights. I have no doubt that there is something out there that can be used to mount a 2 ring system on to that single base.

I do want a scoped double, even an over under so I will wait for one with different scope mounting.

That is a pretty little gun though. I remember that they are built on a 28g sized action, smaller than the 140 action. I will bet the distance between the fining pins is less than 1". The small bbls and light weight will make recoil brisk. That is why they are only regulated with 232g bullets. The adjustable regulation may let you get 250g bullets to shoot at a velocity that produces manageable recoil.