Yes...but requires polarized relays.

(It shows polarized coil relays, but the relays would need to be non-polarized, as most are).

Huh? Where are polarized relays required?

 

The circuit in post #9 could have problems if more than one switch were operated.
My proposed circuit with four 2PST relays would also require interlocking of the buttons circuit to avoid problems.

Going back to post #1, though, the simplest method will be a mechanical arrangement that allows either individual control or operating both switches in unison.

 

The circuit in post #9 could have problems if more than one switch were operated.

How so?

 

How so?

OOPS!! I was thinking of a circuit that I do not see now. Sorry about that , C. I think that comment was made about 2 am.
The circuit does not seem to provide for any shorted circuit paths as I examine it now.