Re: barr&stroud rangefinder
The Barr & Stroud and Wilde rangefinders are differnt brands and made in different countries.
There are some very good units and many rebuilt ones from resellers that may or may not function well. I have seen several rebuilt units that would not hold calibration, but the good ones are fairly rugged.
I bought an original Barr and Stroud several years ago from a collector. I paid $750 and it has been spot on ranging targets to extreme distances (over 10K meters).
Hope this helps