Help ID mystery humbucker

This is in my beloved mid 1980s Westone Spectrum SX I snagged around 2006. I bought one just like it brand new after saving up my paper route, lawn mowing and snow shoveling money back in 1985 but it was stolen eventually. I got this guitar used, always liked the pup and never thought much of it. I recently got an almost identical but red Concord SX so I could try the "correct" stock pup. The red one came w/ a mmk 45. So now I"m pretty curious to figure out what this pup might be.

It's pretty hot, measures over 13k. The wires are green, brown, yellow and white. I'm seeing some maxxon/ibanez that have an almost identical plate, but I'm not seeing any that have only one row of 6 holes. It's not a Carvin, Fender Lead 1, or ancient Guild which are some of the wild goose chases for pups with three height adjustment screws. It seems to be a pretty unique mij three adjustment screws situation, but no markings on the pup at all. It's clearly not stock, someone bothered to dremel some wood out of the way so it would fit. It's wax potted, but it's possible I did that at some point, I lose track.

Any ideas? The back is silver, not goldish colored as it looks in the pic.

Apart from the double balancing screws on one side, it looks like a host of standard humbucker pickups. The fact that its 13k would narrow the field down if you searched for comparable pickups with this impedance and three adjustment screws, but it may take a while to trawl through all the possibles. Anyway, if the pickup sounds good, why worry? Let's rock and roll!

Martin.