Hello Terry. I believe the model number is R171 and it’s not an easy schematic to find. This model does not appear to be listed anywhere in the RCC manuals or supplements, at least not that I can find. I believe that the R171 is very similar in appearance to the model R187 and if lucky, the chassis is the same. Compare the tube list in the attached schematic against your radio and if they match then hopefully this will work for you.