Any suggestions?
I'd use Testor's Liqiud Cement in the Black Bottle with the needle applicator.. Before gluing with it (or with Testor's Pink Label cement), I sand the mating surfaces... Don't have to do much, just take the "shaine" off..
It gives the glue something to work on right away...
If that isn't successful, you could try MEK (Methyl Ethyl Ketone). It's a REALLY hot cement, but it's the main ingredient in Testor's anyway.. The stuff will melt styrene pretty fast... Use it just like Testor's liquid, a good pointed brush and capillary-action... You may have to clamp too.. Get some spring-type clothes-pins...