Welcome to the Forums and the world of Vintage Airstreaming!
I am the owner of a '78 Minuet 6.0 Metre as well. I have a fair amount of factory literature on the Minuet series from '77 through '79 so will be happy to look through it if you have a particular question.
Copis of the manuals are available through Secretarial Services at:
Q: I need an owners and service manual for my Airstream. Where can I get one?
A: The first owners manuals were published in 1964. Prior to that, the owner received a brown envelope containing parts lists and other helpful information on the accessories in his trailer. The VAC has started making these available in the Members Archive section. A service manual with instructions for performing service operations did not exist until 1972.
You can get photocopies of owners manual (1964+) and service manuals (1972-1986) from:
Helen Davis Secretarial Services
PO Box 484 Sidney, OH 45365
Prices are about $33 and $70 respectively. After 1986 the Owners Manuals included available service information.
The above information was quoted from the Vintage Airstream Club web site.
You will need to have your coach's serial number avialble so that you will get the correct manual.
Good luck with your Minuet, and welcome to world of Minuets!