I've got one that's been in this old panel, which never flew, since around 1971. That's right, 50 years. It's in the upper right area. No idea if it works or for that matter, if it ever did. It was purchased as new back then.
The only problem is, this one is also limited to 25 psi, so I'd expect that it will fail like yours did. I'd recommend a different approach, such as one of the electronic engine monitors that fit the same hole.
The missing gauges are the airspeed indicator on the lower left, the altimeter on the top left and the compass, top center.
I'm certainly willing to remove this and send it to you for a decent donation to Doug, beyond your annual dues. However, our postal and UPS offices are pretty busy and I don't want to ship it until my Covid vaccination becomes effective in February.
Dave
And no, I'm not using any of this on my RV-3B project