John, thanks for your comments and helping me understand the various colour schemes mentioned in Roy Bacon's "BSA Twin Restoration" book.
However, when I do an internet search for 1958 Golden Flash motorcycle photos, the majority have a gold lining and I tend to agree with CheeserBeezer on the lining colour. The comments from you both are appreciated - what a great forum this is!
Now I know I need a new fuel tank as mine needs re-chroming which will be prohibitively expensive. Does anyone know the difference between the 1958 Golden Flash tank (42-8102) and a 1954-1957 tank (42-8048)?
Again, any comments appreciated.
Thanks!