So, after consulting with the TDI guru mechanic, I went with is suggestion on not trying to make a problematic used turbo work. I returned that and ended up buying a new GT1749V(B) with the 1 3/8" ALH hose adapter from AARodriguez's fixmyvw.com site. I also got in some new vacuum hoses and misc. parts. And, I'm arranging for acquisition of a Panzer skid plate through the guru mechanic, who was already about to purchase one for his own vehicle.
Not until after I ordered the vacuum hoses did I realize that silicone hoses would be more durable than rubber-based hoses, but I'll swap out the new stock hoses for silicone, perhaps, in a few years.
I didn't yet order any new injector nozzles, but in the future when I'm ready to pay for tuning, I'll buy nozzles then. For that eventuality I was considering either .205 Bosio Sprint 520, or .214 Bosio Sprint Power Plus 520 nozzles, if they wouldn't adversely affect fuel economy or boost power to the point where I would have to upgrade the clutch. But, I don't know at this point which nozzle would be best.
First thing's first, though.