Thanks for everyone's input. They were indeed Clutch Head screws, but rendered nearly oval by someone before me. Managed to get two of them off, but the other two had become rusted into place. Eventually just drilled them out.

But at least I've got the replacement regulator in now.

Many thanks!

Last edited by RevDodd; 04/21/2008 8:42 PM.

When in danger, when in doubt, run in circles, scream and shout.
-- Tom Servo