You’ll need additional circuitry to "upscan" your 3Hz display to 60Hz.
There was a moment many years ago when I considered constructing a mechanical 6502. I quickly learned that transistors are fabricated in silicon for economic reasons.
The fun path would be to modify the display to run at 3Hz (and also implying the much slower horizontal scan rate), but due to the phosphor coating's short persistence, you'd at best see only a small sliver of the full picture at any time. Exactly like you see if you point a video camera to a CRT whose frequency does not match up exactly.
But if you'd take a long exposure photo of the CRT, it would likely work! (EDIT: Might fry your phosphor, though... as for any other components, like filters or components that may get damaged by the now only slowly changing current, I just assume you replaced or retuned that as part of the conversion process.)
