The GE C-545A is in Sam's Photofact #663, C-545B in #802. You may be able to get this information through your local library. Sam's sells copies and can be reached at 800-428-7267.
You should be able to find a similar schematic on nostalgiaair.
Don't have information on your NRI tester. NRI is a school and may have followed another brand tester. There are manuals available on nostalgiaair for some testers. Maybe one is similar.
Norm
: I wonder if there is any tube testing information for the NRI-71 beyond its roll chart. My first venture into old radio will be fixing a GE C-545 AM clock radio with the all america five tube combination. The schematic is probably on this site, but not under the model number I have.
I HAVE THE ROLE CHART, LOOKING FOR MORE.......
It does not show a clock radio, however, the chassis should be the same.
Sorry I cannot help with the tube tester.
Ed.