I've been given a load of old sails to aid the restoration of my 1960's boat. The sails are in good usable order but have gone grey, some have rust marks,and others have the original numbers stuck on, which will come off but the colour of the previous number is still clearly visable...how do I go about solving these issues? Thanks in advance!

See my comments on 'Mags' thread (Advive needed) re the number problem, To be honest when we had sails laundered we never saw a great improvment in the 'grey' ageing you tend to get. I did wonder about this'OXI'clean litter thats been on the box lately might be worth ago. Luckily most of our customers bought new when there sails got that way, the performance gain of new sails was to great a lure!  Barry.

I found that oxyclean added to water and soaking the sails in the bath did improve the colour although they are never going to be pristine.  Rust marks can be lightened with oxalic acid but reappear when the oxyclean is used!!!   Guess it just re-oxidises.  There is certainly a load of muck which comes out of the sails so that must be an improvement. Best of luck (and don't forget to clean the dirty tidemark on the bath when you have finished - yer Ma hates that!!!!)

There's a school of thought that says don't clean old sails as you'll do more physical damage with the chemicals than good. Especially the old Vectis type cloth of the sixties and seventies: this was windproofed and stiffened with a filler material which, if hasn't already fallen out by now, certainly will with most bleaching chemicals. Vectis and its later variants weren't supposed to left with salt in, even overnight.

I'm looking directly at the old Vectis sailcloth buildings from my office it's now YOKOGAWA MAREX TECH LTD & has no connection with weaving sailcloth which is probably only useful in a pubquiz! 
The cloth we produced there that would of been used for dinghies was either 3.7 or 4.3'cima or cima hard' as a resin it was injected into the 'grey' cloth in the finishing process, as the previous comment  the majority of this I suspect would be long gone the effect of these new oxidising agents on the ICI supplied fibre would be interesting, anyone from there any ideas? Or from X windmaster in Holmes chapel like to comment,.....You out there Tom?
I guess the try it & see method as used by many a top scientist might be the way ahead.