When I bought my 75 GL1000 it had been sitting for 18 years.
The bike had been inside and covered but it still needed to come completely apart.
The paint and chrome were in good shape but all the usual things that you have to do on an SOHC4 had to be done. The Carbs had to come apart (a couple of times) the calipers and master cylinders had to be rebuilt, the points replaced, gaped and timed, a few thing that SOHC4's don't have, the cooling system needed to be flushed, the thermostat replaced, differential greased and lube changed and the timing belts replaced.
One of worst things was taking out and cleaning the gas tank, its under the seat and you have to take everything from the gas tank back (and I do mean everything) off except the swingarm to get at it.
This is restoration page for my GL1000,
http://www.peterbylt.com/gl1000.htmAs has already been mentioned Randakk
http://www.randakks.com/ is an excellent source for parts and information, the naked Goldwing club
http://www.ngwclub.com/forum/ Is as good in its own way for early Goldwings as this site is for the SOHC4's. Another good Goldwing site is the Steve Saunders site
http://www.goldwingfacts.com/forums/ I enjoy riding this bike a lot, it gets lots of attention wherever I go, it runs very smooth has lots of power and is very fast.
Peter