6 -7 years ago I bought a book in Ian Allen, called 'Individual Aircraft History of the Boeing 707'. Only 707, but it's all there, far as I can see - Reg Index, Line No. Index, Block No. Index, Maint. No. Index, Customer Ids, , etc., plus 'current' (1998) status, including demised.
By Kivanc N. Hurturk, pub. BUCHair (USA) inc. ISBN 0-9666368-0-5.
Real anorak stuff, but quite interesting.
I would imagine I could answer any specific question you might have about B707's !
You could maybe even borrow it if in the London area, or striking distance.
Don't know how to work the pm system, though. Just reply here.