Yepp, I had a 8842A DMM beyond rescue...
I just used a hacksaw to cut out RefAmp, thought of using Dremel as well, but thought that hacksaw would generate less vibrations, and easier make a straight cut.
Could have made RefAmp board even smaller, but wanted to be on the safe side, and to have somewhere to put mounting screws...
I soldered power +/- 15V directly on Op-amp pins U702 on the secondary side. For Ground, I used the via holes just under the text "C103" (think shield was soldered in these holes originally)
I am not very impressed by the stability though, typical run with FLUKE 8846A below (PLC100), SZA263 in metal box with lid on, powered 24/7 for weeks:
* Min 10.00005V
* Max 10.00010V
* Avg 10.00007V
* SD 7,6µV
* 40000 # samples
So a span of 5ppm between Max and Min, did expect better actually!