I have popped back there this afternoon - couldn't resist the pull of the spring sunshine and a challenge!
It's all very interesting. There are two levels to the catacoombs.
The lower layer don't have numbers over the arches. But the graves at the lower area that have numbers are in section K. My assumption therefore would be that those vaults are all attached to section K. There are three vaults at the bottom that have names Cutler, Patrick and Guest, so these may help sort the numbering out for the bottom section I took some photos of the catacoombs and will attach to a Warstone Lane thread. Attaching one here for reference
The upper layer is simpler because there are numbers over the arches.
To the left of the largest arch (that is adjoining section I), the arches are numbered as follows: 'blank', 1,2, .....9 (I must admit that I had expected them to be numbered in Roman numerals)
To the right of the largest arch (adjoining section J, the numbers are missing - until the last two, which are numbered 10 and 11. Working backwards towards the largest arch (there are 11 small arches), the following vaults have names:
Medlicott (plaque above vault 1)
2 Lucas
3 Harrison
4 Harrison (Above this vault there is a plaque to Adams
Again, it would be worth checking the grave numbers for these to see if they include J in their number. I guess that it would mean noting the dates on the plaque (silly me didn't!), finding a burial number in the library and then Handsworth - or is there a quicker way Wendy?