... and I'll give myself a bit of credit here, because it is due to my post and some email I shared with Dave Smith, the guy behind Retrosheet, that it happened.
I posted about the Retrosheet trouble -- and if you missed it, read the original post here -- on Saturday; due to a server change, they had to change URLs on all their boxscores and player pages.
This, of course, caused all their prior links to be broken. I wrote about this on our SB Nation email list, and I got Eric Simon, who writes the SB Nation Mets blog Amazin' Avenue, who knows some UNIX programming, in touch with Dave and they worked out a way to redirect old links to new links. I don't profess to understand how this works, but it does.
Anyway, that means if you have old Retrosheet boxscores bookmarked or linked anywhere, they will redirect to the new ones. Not only that, but it appears to work faster than the old ones.
At this time they haven't been able to do the player pages, but that might happen sometime in the future.
Good news, and thanks to Eric for helping out!