Searching for VF 12mm

[gfdal]

First of all, I want to say hi to this forum. I'm a new user after being a relativelly recent user of a Bessa R.
2 weeks ago, I had a drama: my 12mm viewfinder fall off my bessa, and with a terrible sound, hit the ground. Result: a broken viewfinder...
My quest to a replacement shows me that this part is extreamly expensive.
So my questions to this forum are:
1 - Is there a "source" for a cheaper 12mm viewfinder?
2 - Would a 15mm VF be an honnest alternative? It is selling half the price of a 12mm...
Again thanks to all

 

[phototone]

A 15mm viewfinder would be a viable option if you did not need precise field-of-view. As long as you knew you would be getting more in your photos than the viewfinder shows.