Cr125R plastic help

Don't worry about price. Worry about finding new plastic. I think '79-'82 fenders will fit, but not absolutely positive. '82 side panels are one of a kind, but close to '80 and '81 Here are a couple of places you can still find them:

http://www.reproductiondecals.com/default_frameset.html?kaw_3.html~main
Note: the above plastics are matte finish, but still look pretty good.

http://www.vmxracing.com/vmx-main.htm
The above are shiny plastic and very good, I hear. But cost more, too.

http://www.amsracing.com/
May or may not have what you need, but great people to deal with.

There are others too. For references and other help, try this site, including "swap meet" and "resources":
http://www.honda-elsinore.com/ (even though the '82 was technically, no longer an "elsinore")

Looks like reproduction decals can fix you up, if the price is right.