Congratulations on your new purchase.

>Valve cover gaskets--leak oil slightly. Can this wait until I do the valves and, if so, when should that be done?

The valve cover gaskets should only cost about $140 or so. But while they have the valve covers off, have them inspect the timing chain and guides. That should answer the timing chain question. From what I've heard, timing chains (AND GUIDES) should be replaced every 100k miles, just to be safe. About an $800 job (that includes the tensioner too). I've had both of these things done to my SL.

BTW, you should only take your SL to a mechanic who specializes in Mercedes (or German cars). I have a great mechanic for all of my other cars, but he told me that he doesn't see very many Mercedes, so he's not very familiar with their common problems and solutions. He recommended a good Mercedes mechanic for my SL.

What do you think is wrong with your valves? Are you consuming oil? If the valve stem seals have never been replaced, they will need to be, but you'll know because you'll be going through a LOT of oil. It may even foul one of your spark plugs. I assume that your mechanic can check the seals while replacing the valve cover gaskets, but it didn't work that way for me. You could pull the spark plugs and check for oil. Replacing all 16 of the valve stem seals cost me $720. Very labor intensive procedure. Takes an entire day for someone who knows what he's doing.

>Steering box--is very slightly seeping. Works great. Replacing with a rebuilt one was quoted at $1K by a local (Bay Area) mechanic, is this a deferrable repair?

Thankfully, I haven't had this problem yet. I seem to recall hearing that seeping is common.

I'm not sure what "front seals" is referring to.

Hope this helps.

__________________
Mike Heath
1988 560SL Black/Palomino
1988 300SEL Black Pearl/Burgandy
1984 500SEC Anthracite Grey/Palomino