I finished overhauling my 732a and I'm very pleased with my first test results.
I put the original Fluke's 334839 CRD that I was able to source into CR5.
Also, VR2 was replaced as original was had some charring on it.
Also, all CC resistors and tantalum and film capacitors (with PP ones) were replaced.
Thermistor accessible from front terminals was replaced with PT1000 RTD.
Initial Results:
10V output is within 0.5ppm from its value before overhaul (I even did a full IPA cleaning of A5 board).
10V load regulation improved from ~2-3mOhm to -0.04mOhm (-0.02ppm change at 5mA load).
Oven temperature is very good at 48.27C (according to RTD).
Unheated SZA263-based reference tempco in 732aTempco of 10V output during 732a heatup is about 0.28ppm/C in my case, this is measured during 732a warm-up.
What is interesting is that it's quite linear during the entire warm-up from 25C all the way to 48C.
Also, temperature rise is also linear with minor overshoot.
Heating over time (blue - temperature, orange - 10V output change in PPM).

10V ouput (in ppm) vs oven temperature scatter.
Curve Fit: 2.778E-01 * x + -8.116E+00

Oven control has little overshoot and looks very stable.

Oven temperature regulation is very good at about 0.01C / C (100x attenuation) (oven vs ambient), it might be even better as my 3458a measuring PT1000's resistance might be a limiting factor.
This will result in 0.28ppm/C / 100 = 0.0028ppm/C ovenized 732a tempco which is much better than 0.05ppm/C spec (18x better to be precise).
