As a follow-up on this one, the cuprit appears to be a toasted 6922 tube on the repro, "modified" by either the U.S. Postal Service, or Canada post. I substituted another 6922, still only some hum & no output, so in my discussions with Dan he is conjecturing that the bad tube has cause some secondary issues. But I'm going to sub. the other tubes in a few days (when they arrive) just to see. If it is still a no-go with all new tubes then it's getting shipped back to Bottlehead-town for a full analysis.
I also tested the cables (XLR-to-RCA) for continuity per Dan's suggestion, to confirm the pins are correct, they check out OK.
BTW, I did run the Otari's output into my phono stage, you could hear the deck's output, although not great sounding, presumably due to RIAA eq. & output differences. On the other hand, running the output of my turntable into the repro yielded no output from it, only more of that low level hum. So I think my Otari has a clean bill of health, except for those VU meters showing constant signal when there isn't one; I'm a bit concerned about this. I'm going to try and dub FM or an LP and see if the Otari records OK.
Again, thanks everyone for their help on this one, this is what makes this audio hobby a great one.