You should join the Rangefinder Forum (RFF) (
http://www.rangefinderforum.com/). They have an active group of Yashica users. You might also be interested in the Yashica Guy Web site (
www.yashica-guy.com). He has technical and repair details for Yashica rangefinder cameras and is also a good source for battery adapters.
As for performance...I have never heard a complaint about the Electro 35 series except for the "Pad-of-death" shutter release issue and availability of batteries. They have great optics and were very popular cameras through the entirety of their long run.
Steve
P.S. RFF is not responding today. Hope that it is just a matter of a technical glitch.