What's the date code on your flexible brake hoses? Most manufacturers state replacement every 5 years regardless of mileage (thread incoming ;) )
I'm +1 with pdg on the brake hoses. Friend of mine on a pre-2000 R1100 had his brakes lock up because the inner wall of the original rubber brake hoses were shedding flakes which blocked the line. Old story but bears repeating frequently. Big safety issue.
+1 on everything else too, except I'd probably just blow out the filter with compressed air and not necessarily replace right away. I don't think those things have an expiry date, they're not cheap and are good for 15k miles or more. Maybe you can find the mileage of the last replacement in the documentation.
But if it were me, I would keep the $$ investment minimal until I know it runs and have had a look at he splines. So -- good battery, fresh fuel, pull fuel pump and do the goo check, bottle of techron and hit the starter. Wouldn't invest anything in tires until know how it runs and how the splines look. My k75 started right up after 3 years and I didn't replace anything but the battery and add some fresh fuel and Lukas fuel treatment. If it doesn't run without too much coaxing then you may have give it a thorough inspection i.e. splines then do the cost benefit analysis based on the whole picture rather than just what you see on the outside.
Runs + splines ok = keeper. Then you get to start thinking about spending the $$ to make it safe to ride.
My two cents -- worth exactly....two cents.
