Thank you very much gents for the advice.

@Mark, good points there. My friend Shimizu San in Tokyo is shooting his Heirinkan with two piece mounts; I will ask again what they are. He wasn’t sure last time I asked ha-ha.

Moving the one piece mount to the rear is a good idea. This scope is exactly what Heirinkan meant to use;
it’s depicted in their folder. A rebrander Nikko Special 4x20. However I wanted to use something else, probably my Kassnar 4x40, with higher mounts. I enjoy my shooting much more with good optics.

Another option would be to simply use the original peep sight which I have.

@Geezer, thank you, I will have a look at BKL mounts.

Cheers, Louis