OK, wrenches went in mail today. Good luck.
I swapped out my Gl*******s overflow yesterday and the new Eshopps one was leaking very badly from the two bottom bulkheads. Really make sure to seal those up before you install the new overflow. And I used the Magic Lube from gl*******s on the bulk head through the tank and that didn't leak at all. I will likely have to disassemble everything again, remove the two bottom bulkheads and reassemble them with the Magic lube.
Replacing an overflow is such a huge pain. Best of luck.
FB