Zeiss made a combined 85-135 finder, several companies made turret finders with multiple focal lengths, and KMZ made a single focal length finder for the Kiev (Contax copy) that is fairly common, and can be had for a low price (plus shipping).
Best deal I saw was $20 for the finder, and free shipping, with the plastic case and "passport". Only thing with the KMZ finders is there is no parallax correction, and sometimes you get one glued together at an angle, so all your photos wind up with a slant if you don't compensate for it.
Zeiss also made finder adapters for the II and III that fit over the front and back of the viewfinder, but they are a bit more expensive.
https://www.ebay.com/itm/Zeiss-Ikon...9YAAOSwMflcGsj6:sc:USPSFirstClass!24019!US!-1
https://www.ebay.com/itm/Zeiss-Clip...665674?hash=item4432a8490a:g:NyUAAOSwvENcFF3E
PF