I am looking at a couple of mid-size double rifles and want to get some information about the makers and their quality of work.

Does anyone have exoperience with guns maanufactured between 1950 and 1980 by

• Josef Winkler
• Buhag
• Chapuis

I have heard of Chapuis and Winkler but really know nothing about the quality of their rifles. Buhag was a Suhl, East German gun cooperative that handles sales of East German guns.
Any first hand information would be appreciated.