Thanks to all who replied. A CR member emailed me the 1974 catalog I couldn't seem to open on the RetroRaleighs site. It clearly shows the old style decals. So, if you believe the catalogs, the Reynolds Tube Co. decal was first used on Raleigh in 1975 or 1976 (there is no 1975 catalog on the site). I'm going to assume my square Reynolds Tube Co. decal is not original and replace it when the frame is repaired.
Studying the catalogs also cleared up another point of confusion for me. I thought the large-rivet Brooks Team Pro was introduced in 1974, but it is already shown on the Professional in the 1972 catalog. There is no 1971 catalog on the site, so the Team Pro could even have been avialable in 1971.
Regards,
Jerry Moos
Houston, TX