If it was stored properly (and it sounds like it was), not much I expect. I would gas it up, install the battery, start and see what you get.
When I bought my 550 last year with 7k miles. It had been stored, with gas in it, since about 1986. So everything was very thoroughly gummed up. It was completely original down to the brake pads, tires and tubes.
I had to clean the tank and carbs and I replaced the fuel lines and tires/tubes. The brake fluid had evaporated to a small jelly on one side of the reservoir, but I cleaned it and flushed the line, and it worked great. I ended up having to replace the fork seals and the speedo cable. But I left the rest alone. The original chain, points, brake pads/shoes etc. I put over 4k miles on it in about 2 months before I sold it in August. The only problems that I had were a cracked floatbowl overflow tube, a stuck oil filter bolt, and a loose condenser screw (which was my fault).
7 years isn't that long for a bike stored in a climate controlled environment like a living room, the o-rings could very well be in fine condition. I would wait for evidence of leaks before I replaced them.