http://www.trapdoorcollector.com/FAQ.html
1.
WHAT DO THE STOCK MARKING MEAN?
This is one of the most often asked questions! A few such markings, such as DETROIT BOARD OF COMMERCE are relatively straightforward, but many combinations of initials have never been deciphered. The Regular Army did not so mark their weapons, however, a GREAT many trapdoors were used by State militias, National Guard units, volunteer troops, etc. during the war with Spain in 1898. Most of the markings which consist of a LOW number, over a letter, over a (usually) higher number, date from this period, and a marking such as 2/B/27 is generally construed to mean something like SECOND (fill in your choice of State) INFANTRY, Co B, RACK (rifle) #27. The problem comes in determining WHICH State, or group, is meant. This is a field ripe for research, but it will be a daunting task. One place to start, aside from OLD, well-proven, museum holdings, might be to attempt to contact the owners of SRS-lettered guns, where the number was attributed to a particular State, and see if any marking pattern can be established. Sadly, I suspect that, so long as the information itself was correct, different marking designs would have been permitted - even two companies of the same regiment may have had a different STYLE - there are many ways to mark 2/B/27, any of which would have satisfied the needs of the user.
Deadlydaring
