Plastic model ruined-Please help

Heres what happened, I primed a plastic model car with a can a testors white primer with the intent of painting it with a lacquer paint. I was later told to strip the white primer and use automotive light grey primer instead because the testors white primer and the lacquer paint would react badly together. So heres what I did, I stripped the off white primer and then dipped the entire model in a bath of lacquer thinner thinking this would help prep the model for the lacquer paint, the model now appears to be ruined as Its covered with shiny blotches thru out. I think what happened was I still had a good amount white primer on the inside of the model and it mixed with the lacquer thinner and caused a bad reaction. I tried to sand the model to get the blothes off of it and it didn't work. I was thinking of dipping it in Castro Superclean to see if that would clean up the model again so that I can prime it with the Automotive light grey. Please advise as I'm very disappointed since this is a vintage 67 mustang that I'm trying to refurbish. Thanks..