I just made contact with a SCELBI employee, who added some details about the power supplies that SCELI made. The power supply design that I’m talking about, is the one seen in the CHM’s online catalog.
http://www.computerhistory.org/collections/catalog/X714.86A
This is one of no more than 20 that were made. The same design was used for both the 8H and the 8B. The design incorporated 2 standard Power-One linear supplies. A 5 volt version and a 12 volt version. The 12 volt version was modified by SCELBI to produce 9 volts.
The enclosure was lettered with rub on lettering, which was then clear coated with lacquer.
That’s good information to have. I was speculating whether Power One supplies were used. They were very widely used in electronic equipment around the time the Scelbi was being manufactured.