A few days ago I posted about my heater control panel split in two and one side split asking about methods to repair or replace. I had a few good responses, so thank you for those, including a link to buying second hand one from eBay. I was about to go for that but then thought about repair and remembered reading that most plastic auto panels will stick with cyanoacrylate based glues (superglue) as it softens the surface, but you have to use it quite sparingly and not overload the joint with glue. I cleaned the joint areas with acetone solvent (nail varnish remover) which itself has the effect of softening the surface so don't use too much. The joints can then be carefully joined and I used a cut up hotel door card, after the initial joining of the parts, and glued these across the joint in critical places to reinforce it. I think it has worked rather well and so far seems strong and well glued together. Photos below