The one I had was a Gibson Spirit and you could see the Epiphone lable outline under the Gibson name. It had a single Tim Shaw in the bridge but there were 2 pickup versions too.
"The Gibson Spirit is a lesser-known model produced from 1982 to 1986 by Gibson in the Nashville, Tennessee, and Kalamazoo, Michigan, factories. It was initially produced in the Kalamazoo factory under the Epiphone nameplate. In response to poor sales, some Epiphone models were changed to Gibson, and a faint Epiphone logo can be seen under the Gibson logo on the peghead."
Anyway, if this is what you have I wouldn't mess with it. Buy a PRS SE Soapbar and put a mini-humbucker in the position of your choice.
Mine looked exactly like this one: