The mounting hardware for the toolbox is, as far as I know.
The green strap in Henks photo use's 2 round head slotted screws and nuts, the same as used on the front mudguard stay.
The same screw and nuts used on the tab, some people us bolts.
The clip, that can be hard to find, has a spacer washer inside.
The green bracket, were the tag is, fastens to the muffler bracket by means of a long bolt and washer.
I remember a disscussion awhile ago about contract plates mounted on the toolbox.
I see that on the bike, I guess that it is yours? early deluxe, with slotted knob.
Is the plate original to the box? Need to mount mine somewhere, have teardrop rear light.
The toolbox is replaced recently for what I think is the correct one for my BSA. The few old photos I have of BSA's with a torpedo tail light, or MT1130 as they are actually called, that also show their contract plate made me decide to do it like in this photo. I must say that I had to drill the holes for the contract plate in the tool box myself.
I actually think it's done like this on the KM20 BSA's with an MT1130 tail light and very likely done with the early WM20 BSA's like my WM20 2415.
The Lucas MT 1130 was officially for the 1940 model year only, but they did start using them on the WD 'K' models. It requires a special number plate with a dimple in the top for the foot of the lamp (I think Jan still makes them). They were also used by Ariel around 1938/9. Ron
About Poysers spanners.
I've had a look around Australian tool collecting sites & such, but I can't find a reference to them as a brand or company name.