Gotta love mitre saws. Chopped the crappy fixtures off that old cannon in no time at all. Then I bought actual Schedule-40 fittings from the sprinkler shop down the straight. Cost an extra $5, but it's worth it for the safety.
Then, since it was our anniversary, Eri helped me put it all together. We used the high-pressure "blue glue" and made certain to twist at least 90 degrees as we inserted everything. We also redesigned it to use fewer fittings, which made the twisting phase a lot easier.
Working together, and being extremely careful, it took us about two hours all told. We left it in the sun, and after about 5 hours of curing, I'll try it at tonight's performance of Hairspray!