I assumed that the tools in the drawing were more or less to scale.
The 16H has a six-incher that would be replaced by a generic WD 7" item in the event of loss, according to the 'Equipment to Scale' lists that turn up with some of the parts lists. Are there any BSA equivalents ?
Is the photo showing up now? It's showing up for me. Apologies if there's a glitch for others. Based on Rik's brief above, it appears to be postwar. It has the closed-off slot, like Henk's, but it has the longer thumbnut.