I am attempting to replace the beamsplitter in my Kalart Rangefinder. A few questions.
1. I have made a shim since the new splitter is thinner. Does the glass go to the front of the guide?
2. I realize the mirror surface needs to face the front. How can I tell which is the mirror surface on a beamsplitter? I did a test with a light, but it's hard for me to tell which surface is brighter.
I've attached a photo of the rangefinder.


Thanks,
Mark Z

Frame-shim-mirror, the front edge of the mirror needs to be as close as possible to where the original was.

Hold the beam splitting mirror at a 45° angle, top rearward and side lit, the coated side will be shinier when to the front.