The Bristol Sycamore had vacuum instruments. I can remember flying them fifty-six years ago and having to ignore the artificial horizon when transiting because of the acceleration errors. There was no way you could topple them: You were confirmed to be, or soon to be, dead if that happened.
You can see from this picture the characteristic slant of an artificial horizon with a lack of vacuum.
Edited to add. This picture appears to have an electrical T&S but I cannot remember what a vacuum T&S had on its face.
BRISTOL Sycamore Walkaround
