Not sure I understand. Hot 255V neutral vols.008 to .8. ...What?
The fixtures never worked and the building is from 1998 with FPE Stablok? Sounds like the electrical contractor was cleaning out his basement.

Have you tried using 130V PAR 38 bulbs?

Just thought,...with 32 fixtures, I’m guessing you would probably have several circuits to deal with. If they are fed with multiwire branch circuits and you have a loose neutral connection somewhere when under load, then you could potentially turn a lot of those PAR 38’s into flash bulbs.
You might start by checking connections in all of the light junction boxes themselves.