Actually, mine is called an Ultraflex.
Interesting tid-bits on this rare amp. I had found the same web site, but that's about all. I guessed that the amp was originally designed for full-range use for piano or vocals since it has, as you say, two separate finals, one driving a small OPT into a small speaker, the other driving a larger OPT into a larger speaker. I took that as a sort of bi-amped two-way design. But maybe it was more for effects than an attempt at full range. A friend used it to amplify an accordian, of all things. He gave it to me when he moved out of state about 20 years ago. Not to hijack this thread...