10 across-mark of prosperity in olden times (4).The letters are F-G- I think;the clue ties in with 7 down which reads - Fibrous material provided by engineer initially not goin' bld(7).BTW that is exactly how it is printed,so I'm not sure if it's deliberate or not.Any help much appreciated.
Firstly either the F or G must surely be wrong so please give the clues that yielded those letters!
Secondly, assuming that bld is a misprint for bad, it lloks like an anagram of RE + N + GOIN - but that only gives negrino which is a coktail and not a fibrous material! Alternatively it may involve a word for 'going bad' without the final g (eg. addlin). Sorry not to be any more help but it might spark sthg with someone else.
Quizmonkey and Shamrock Blue,having read the clues again,I made a complete horlicks of that corner,so can't post it off.many thanks to you both for your help.Regards.
G.