Update 21 July 2011
I have just been advised by the author, Robert M Stitt, that he has prepared a 34-page additions and amendments document for this book. It is available from the Mushroom Books website; here is the link to the product page which has a download link on it: http://www.mmpbooks.biz/ksiazki/123/#765
Lots of valuable information -- the author and Mushroom are to be congratulated for this all-too-rare effort.
This is Mushroom's 100th book, and a grand one it is!! It's 248 pages in their fairly new A-4 format and although still a soft-cover, it includes a dust jacket with ads for about 18 forth-coming books, including the much anticipated (by me) Gloster Gamecock and Grebe and another in the Gladiator series.