Hello Frank, The instructions supplied with these guns as new are very basic, it may be better to look a T W Chambers website, where they have exploded diagrams of all models, which can be printed off and studied...they also sell spares.
http://www.gunspares.co.uk/shopdisplaycategories.asp?id=23960&
...just click on BSA and then your gun.
There is also a book by Q Cobham, about air rifle repair, I think it is out of print, but they appear on various book websites like abe books, or on ebay from time to time.
The title is;
Air Rifle, and Air Pistol maintenance and repair,
Perfect Paperback: 208 pages
Publisher: mini-maxi publications (May 2006)
Language English
ISBN-10: 0955313104
ISBN-13: 978-0955313103
Hope some of this is of interest / help, I am sure your problem is a simple one, and also that it is easily fixable, have you tried near you to contact an air rifle club or gunshop that maybe could help?
Best regards, Eddie