Adapting 21mm CV finder to also frame 21mm lenses?

[yanidel]

I have no knowledge on glass techniques so I would like to know if there is a way to adapt the CV 21mm normal finder (that I use for the CV 15mm lens due to the crop factor of 1.5) so that I can also have the frame for the CV 21mm lens on the same finder ?
Hope this is clear ...🙄 and that this is not asking too much.

 

[Jim Watts]

A friend just masked one down with black tape, but thats not an option if you also want to use it as a full frame 21mm finder. Personally I find the 28/35mm VC minifinder the best for 21mm lens on the R-D1.