I can't find my original thread asking help with stripped out socket heads. It was the inside 6mm socket on the passenger side that was the problem.
Suggestions were drill, grind, drive a torx into the socket head, JB weld.
Here's what happened:
All methods involving grinding a 7mm hex to fit and driving it in failed.
There is no access for either drilling ir grinding.
The JB weld had some initial success--I was able to turn it about one turn before it failed. Subsequent JB weld attempts were futile.
Here is how I got it out.
I removed the engine shock and was able to rotate the motor mount about the inner screw, counter clockwise, about 1/3 to 2/3 of a turn. This permits much better visibility of the offending socket head. By removing the Air Cleaner, and its bracket, it is possible to snake a 3/8 drive extension down past the exhaust manifold and to the screw. This is how I got access for the JB weld attempts. After the failure of the JKBweld, I sacrificed an old 4mm hex socket. It dropped into the worn socket head with a lot of slack. Then I welded the 4mm hex to the worn socket head. Factors that help are--the mount is aluminum--sloppy welding will not weld the screw to the mount. Negative factors--seeing what you are welding--an automatic helmet would make this child's play. I had to align the rod, but not strike the arc, and then lower the face shield and blindly strike the arc. It took a while, but I finally got it done, while managing to set the rubber part of the mount on fire. The welded hex extracted the worn socket head, and I was able to remove the burning mount.
The key is rotating the mount to gain visibility and access.
New SS socket heads were liberally coated with never sieze, and installed.

Two thumbs up! Congrats!

Even with all the assistance you got here you still got 'er done!

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Rob M
Norwich, VT USA
1980 240D Euro delivery 4 speed manual silver/blue
~160K miles

one of the little allen mount bolts?

we broke one last week. we drilled it all out and put in a longer through bolt with a wascher and a lock washer.

wascher is the german spelling. heh, heh.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Well done! Or, ... weld on...

I always fear those things stripping out.
You deserve an award, beer, something.