Hold on now guys, we're answering a question based on far too limited information.
Tom - When you say "restoring" a K6 it could mean anything from touching up a few paint blemishes to its needing a full refabric and refinishing. The latter would I'm sure be too much for a university gliding club to tackle - too much time, effort, cost and skills set.
Let's start from the end, not the beginning. The K6 unfortunately comes under EASA (European Mindless Bureaucracy) , it's not Annex II. You will therefore need an Airworthiness Review Certificate (ARC) issued by a BGA Chief Engineer before it can fly and the type of materials to be used are therefore more restricted than Annex II.
If the glider is, or has recently been airworthy then one of your host gliding club's Chief Engineers will have issued the last ARC. and he (or another glider inspector) will have done the annual physical inspection. Track those guys down and ask their opinion before doing anything. If the glider has been recently airworthy then they can tell you if new fabric is really needed (probably not). If the glider has not been recently (i.e. in the last couple of years) airworthy then forget the whole project right now.
Also the Chief Engineer will have an opinion on the paint to be used. Because if you paint first, and then ask him to sign off the glider, you might be told where put it!
The glider logbook ought to tell you what finish was last used and you would be well advised to stick to that type as a recoat. Otherwise there can be very nasty reactions between differing paint types. If you do start applying paint over an old finish, do some small inconspicuous test dabs to make sure there isn't a reaction. Not all glider owners pre-EASA were totally precise about recording repaints etc!
Incidentally one of the main problems with the K6 is cockpit size. Taller pilots (i.e. me) just don't fit. It can be a major problem for a club glider. Check whether your potential pilots can fit into it before doing too much work.
If out of interest you want to see how to refabric a glider Google the Ceconite Manual - it's very comprehensive.
P.M. me if you have more questions
cheers
Dave