Norbert. Your frame is the early type with no rubber mounts used. Sorry to say your tank is a solid mount as standard, the parts you list are for the later frame and tank. They called it progress.
Mitch's link above shows detail of this later mounting. The later frame has a larger hole at the front (20mm bore) into which the pair of rubber sleeves 67 8108 and metal bushes 678109 are pushed in from each side of the frame. The tank front then tightens down onto the steel bushes, isolated from vibration by the rubber sleeve. At the rear the later tank has rubber bushes (not shown in the parts book) but the same metal bushes. These mount onto a through bolt, but in fact a length of studding/threaded bar and nuts and washers works better. and gives scope to align the tank centrally and keep it there. Not for the purists. The 49/53 & 54/57 Parts books also shows two different rear mounts, for the two different tanks. In short any combination of frame and tank can be made to fit, the basic fixing points are the same. You can end up with no flexible mounting, flex at front and back , or flex at either end depending on the tank and frame types. This reiterates the sentiment of the BSA Service Bulletin above.
Some Tanks have provision for a bracing bar between each side of the tank underneath at the front, often missing, it's a simple metal strip onto a couple of downward pointing studs. Designed to keep the two halves from flexing.
Use spacing washers between the frame and the tank front mounting to avoid strain on the tank as you tighten everything up.
Swarfy.
