Thanks Gav, yes that is the factory stand, it actually slides all the way up the center shaft of the frame. I believe it was only done for the first few hundred 1947 A7's produced, and then as Trev has mentioned, was known to be quite an issue hahaha
some reports say they fell down as people were riding them., I know for a fact it is a pain to lift bike (straight upwards) to get on stand, and before some minor adjustments, was quite easily dislodged in the lock and would fall over :/