Re: shaking and noise from rear!
the vibration may well be a chunk off rubber doughnut come off, especially the rear one. Often an issue, especially on an oder car as the rubber can perish over time.
The instrument issue is probably a faulty dimmer switch, my car does the same, bash the dimmer and it goes away.
IIRC there is not a bleed screw on the rad (may be different on a 2.0 TS), just fill up via the expansion tank, start up with the cap off and the air will eventually come out.
These issues are typical of a 75 at this age, niggles, not a sign that you have bought a bad 'um, just a test before getting your badge of honour.