There's two things to report.
First.
I had sent the Ebay seller an email message and got a reply back from him saying that there must've been a mixup in cleaning and reassembling parts and he's sending me a new right shifter on his dime. That's absolutely awesome. I couldn't ask for any better customer service.
Second.
I did take the shifter apart this morning and found that each side shifter lever and housing is cast differently. So in other words, I can't just flip the rachet wheel and the ratchet catcher thingy and spring- the lever is cast to accept those parts in the way they need to be held for the ratchet to work in one direction.
There's two other issues that now have arisen out of this- one of the new shift cables is starting to fray, having been installed and removed 2-3 times. That's just a couple of bucks.
The other thing is that the cable clamp on the FD is now stripped out because I'm a dummy and tightened it too far. So I'm going to head up to the hardware store and get a nut to put on the other side so I don't have to buy a new FD. Hopefully that'll work.
This bike is an adventure.