This stamp is a relief T or relief B. The heavy cancellation makes a quick relief ID difficult. I am leaning toward relief T. Stamp to right eliminates column 10. It is single recut top and double EC recut at bottom. This narrows it down to 16 positions. As I notice the stamp to the right is lower, this eliminates 2nd and 7th column on left pane and 4th, 6th, and 8th columns on right pane. This drops it to 12 positions. As I start checking for plating marks, it becomes evident that the first position that I checked is a match, 6L1L.