Date registered: Sep 2004
Vehicle: 1985 500SEC, 1991 190E 2.6.
Location: Los Angeles / Hannover Germany
Mentioned: 11 Post(s)
Quoted: 937 Post(s)
Some of the better sets have sets have kind of a female easy out socket.
Meaning the socket is slightly conical (flared inside) and has a raised left hand thread inside.
The thinner the socket walls to allow clearance into tight bolt holes, the better the steel has to be. Same for the raised left hand thread inside.
Some of the sets have smaller sizes, and a second companion set for larger bolts you would require.
Hammering on a socket works on regular hexagonal bolts, but your lock bolts heads are round, so a socket hammered on is likely to slip imo.
The lock bolt you pictured has perhaps more than 100 variants, so realistically there is next to no chance to find the matching key.
I am just speculating here. Perhaps you could find something to fit tightly into 2 points of the star insert of your lock, like the flat screwdriver bit of an impact driver (they are reversible, make sure the impact driver is set for left turn).
As last resort, a top of the line reversible impact drill with a left turn quality drill bit for hardened stainless steel might work. If that still doesn't do it, an ez out on the drilled hole would be the next step.
I have seen people use a chisel, but even those good with hammer and chisel always leave marks around the bolt hole of the wheels.
Yours are not the wheels found on most W126, but perhaps used on last years of the model (?).
They are a common style on later Mercedes (W202, W210, W140, etc), but in different size and offset though. Once you know the specs, size and offset of your wheels, it might be easier and cheaper to just drill out the bolt, and find another like wheel from a wrecking yard etc. Again, a left hand drill bit is preferable, as its turning in the correct direction. If the bit gets enough bite, the bolt may come out.
If I remember correctly, ElRojo has these wheels on his 560SEL. He would know the specs you need.