FYI: Keys for 80's 123s are easy
 

Don't pay $30 to a dealership. Many locksmiths don't have any idea when they look at your key compared to the books- because our cars are old enough that they're not in the books. My local locksmith kept the old books around, was able to make a copy for me. I have an 84 300D. The key blank that you need is "X83" or "MB39". Mine is an Ilco brass key. I know a lot of you want steel keys, but I'd rather have a bunch of $3 brass keys get worn down than the brass insides of my lock getting worn down by the steel key. Hope this works for you, and good luck.

so you can get a factory original key from the dealership??? with the black boot on it??

Yes, I got a couple too.
Try getting a key for a 116 though...

No, it's a plain Ilco brass key. I'm going to powdercoat mine, though. If anyone wants me to powdercoat their keys or other small object, I should be able to do that after Christmas this year.

Actually, when the brass keys wear down, they leave behind small shavings that eventually destroy the lock tumblers.

I got a key from the dealer. I'm looking at it now. I don't think it's brass...but what do I know? This thing is brass?:eek2:

speedy is right
 

$48 for 2 OE keys from the dealer was harsh, but its cheaper and less hassle than changing a tumbler.

Nevermind, I think I read things wrong. This key is cold, hard steel. :D

when in doubt use a magnet

i agree, i think it is funny when i advise customers to trash their brass keys and get OE steel keys, but they continue to use them the a month later the car is towed in with a key that won't turn. amounts to pay me a little now, or pay me even more later.

I still dont understand. A brass key on brass leaves doesn't leave shavings unless it is nickel plated. Right? Steel is much harder than brass. Why would you want to rub hard steel on little brass leaves? Plus, $25 per key? I know we all want to avoid having to drill out a steering lock, but again, how do metal shavings get in the tumbler from a brass key if all it is rubbing up against are brass leaves?

Get both, keep the cheap brass keys as a spares and use the new steel key everyday.

Don't use brass keys, as the others have said. I think the brass keys is what destroyed the locks in my old 300CD.

the keys for my 123 from the dealership were much lower quality than the oem ones... the plastic is much softer and bends:(

those are oem, for some reason on the new cut keys for the 123 mercedes uses the cheap plastic head, which with time will bend as you said, i have collected some used ones to replace when i am working on customers cars and they rip, just to avoid problems. you can also buy them as replacements from mercedes.