The meaning of Dunhill's OD designation has been pretty clearly defined but I wonder about the use of letters on other British makes. I have a few Sasieni King Size pipes...two are patents with small dots, one slightly later with no patent and somewhat larger dots but still "family era". None have shape numbers or town names, but are stamped with the letter "B". I think later iterations were stamped with a "G" or "SG" although I could be misremembering. I recall when Bob Havens (Milwaukee) began his estate business in the mid-70's (taking over from Fritz Felcone,of NJ) he put out a wants lists including King Size Sasienis but only with the letter "B". I also have a Comoy's 342 billiard, but have seen Comoy's 342B as well. I note in the 1956 Comoy's catalog newly reprinted on this forum there are some shapes with an appended "C", etc, and I have seen some Barling's such as the 71A. So how, for instance, is the Comoy's 342 different from a 342A? I assume these letters must have SOME significance.