Many thanks to the respondents here. A few points I have picked up:

1a) Re pellets, I bought my first tin in many years and almost had a seizure to find the price was £12.50 for Superdomes. My first tin, in 1972, was 28p (Marksman - I still have the old tin). I suppose this is par for the course. Yesterday, I tried some old Hobbys (flat heads) and these were pulverised by my Webley Mk3 - no outer or inner skirts left when firing on a flat steel target holder. So, I shall probably try to obtain some more and presume they will also do well for a BSA Standard.
b) Given the demise of Eley Wasp, I am surprised a German company has not entered the market to fill the vacuum as they could produce a .22 replacement (5.6mm?). I wonder if the Americans produce anything in .22, given they still use imperial measurements.
c) I was told from the gunsmith, today, that Milbros have just packed in - which provides more reason for a German company to clean up in the market place.

2 Many thanks, Phil, for that helpful insight on stripping the BSA Standard. I have filed it in Word and am waiting to speak to the recommended repairer my gunsmith suggested. If he is up for it, I will furnish him with this information.

3 Someone, here, could make a tidy sum repairing collectors' guns. It might be worth a new thread suggesting this, for the help of members. Would anyone like to start this hare running?!

4 Generally, joining this site was a colossal help. The information from fellow collectors is vast. I must visit a fare of some sort, where like minded people attend. If anyone knows of anything in the SE, please advise.

Rgds
Andrew.