Agreed.
Much as I hate to admit it, I think this is probably correct, too. I thought I was very careful when removing and replacing the radiator and associated hardware, but it just seems like too much of a coincidence for it to be something else at this point.
All those parts are present and accounted for. When I removed the radiator, I didn't remove anything else that wasn't required to get to the radiator. All the hoses I detached at the radiator-end connection, leaving the other end intact wherever it was attached (i.e. water pump, drain hole, etc.). Maybe we cracked a hose getting it off (or back on), but it appeared to me (what little I could see) that the water was coming from the underside front of the water pump. There just wasn't a way to see it without sticking my face into a spinning fan blade.
Thanks, I hadn't thought of that. Pressurizing it without the motor running would make for much easier inspection. I'll try that this weekend.
To the poster asking about messing with the thermostat - my thought process was this: Okay, now that the radiator has been fixed, there's this massive leak coming (apparently) from the area where the t-stat is installed - that wasn't there before! Maybe the radiator wasn't working before and now that it is it's sending fluid down that hose and it can't go anywhere because I installed the t-stat wrong or maybe the t-stat is broken...while I'm elbows-deep here maybe I better check it...
Anyhow, I tested it and it's working. And I apparently had it installed correctly (spring-down, toward the water pump). So something else must be the issue.