Ran across this at
http://www.saxophone.org/museum/publications 1965 Frank Holton catalog. The third clarinet from the left has the kidney bean touches.
I have a Vito Resotone (no number designation) that has them, and it also has a serial number that doesn't match any of the lists I can find. 9408F It has the oval Vito logo on the top joint and ringless bell, and the serial number only on the top joint. I was beginning to think I had a Frankenstein, but due to a frozen key on another Vito, I found they were interchangeable with a 1983 resotone 3 model 7212.