83 KZ1100 shaft head and base gasket leak

My KZ1100, with 27k miles, is leaking oil from the head gasket and the cylinder base gasket. The entire engine was covered with a light film of oil/road grime when my son brought it over. He rides the heck out of it trying to keep up with his crotch rocket buddies. So I rode it to breakfast today and it runs great. Then took it to the car wash to clean the engine so I could spot the source of the leak. Dried it off and rode it about 5 more miles before I put it on the lift. I can see fresh oil on the front of the engine from the center of the head gasket and center of the base gasket. I should have taken some photos.

Here is what I've done so far.
pulled the spark plugs. All a look lean but #4 carboned up. No sign of burning oil. I'll have to address this later.

re-torqued the head nuts, all but one between 2 and 3 on the 3 side, were still tight. That one was only slightly loose. About 1/16 turn to torque to 29 ft lb. The two outside bolts were also a little loose but not leaking there.

All valve cover bolts were loose but it's not leaking from the valve cover.

Plan to run compression test tomorrow to see what's up if anything.

Ok long winded but here is my question:
If replacing the head and base gasket would you guys go ahead and just do rings and have the valves gone over? If compression is good and the bike does run well with no smoke would you just replace the gaskets and leave well enough alone. I probably will sell the bike in the next year so longevity is not a concern.

Thoughts?

I forgot to mention that I did the valve lash summer of 16 about 3k miles ago. Still anxious to see what compression check shows.

Common leaks. I'd change the valve guide seals while in there.
Steve

Thanks Steve, What about the upper end rebuild or just replace gaskets?

You'll see when you get in there. Be sure you get all the carbon dust and crud out of the bores. It will scratch the hell out of them.
Steve

Good tip. I have in the past spun the pistons to TDC and wire brushed them then vacuum up the dust. Never thought about the carbon scratching the bores. It just made sense to me to clean it up thereby reducing the crude falling into the crank case.

Unless compression is low I'd reuse the rings considering you are going to sell the bike. I'd replace the valve stem seals as Steve mentions. Stay away from Athena gaskets unless you like to redo the work.