There are few better than Plastic Weld.
Five star adhesives do a good solvent , can't remember it's name but it works well.
Dichloromethane (?) is the stuff in them both.
If you leave the top off the bottle the active ingredient seems to evaporate leaving the glue apparently useless.
Freshsolvent can be assured if you use a dispenser. These are a few quid and worth their weight in gold