We all know that the guns are numbered in hexadecimal, right? A legacy of decades of 'coading,' i presume.
Apparently, small fields have 10 (hex = A) numbered guns (gngs,) medium have 13 (hex = D) and large have 23 (hex = 17.) So, the town guns start with B, E, and 18 (S,M and L.)
While not showing the locations, guns in town can be checked with the downtime dot command, and counting the eight highest numbers in sequence. I always forget how many guns are on each field, but it is an accurate check.