Thank you, again. It's starting to make sense. This is a 1970's Studio Lord single cut. I bought it in a Ebay auction from a seller in Japan.
I am hoping to put a 489t in the bridge and a SH2N in the neck. I've sat through the "Install Pick Ups in your guitar" online course that Seymour Duncan made available. But haven't done any of the soldering yet. I am also hoping to install one of those PureTone jacks. I hope not to make much of a mess.