I have managed to source a new grip pad for my standard FWB 150, but can anyone advise me if the FWB 150 rifles originally came with a plastic butt plate spacer, or if the rubber grip pad just screwed directly to the end of the wooden stock with no spacer in-between?

If they came with no spacer, then the rubber grip pad will be non-adjustable.

I also have a 150T and the grip pad on that model is fixed with no spacer, but I have seen other (non T stocked) Model 150 rifles with spacers, so maybe these were an option available at the time, or maybe they were retro-fitted later.

I have also seen some with adjustable butt grips fitted, but I am guessing these may have been taken from the later 300S rifles?

Any information about what butt plates and grip pads were supplied on the different variants of the 150 models would be appreciated.