I hate end panels dead on size! Who ever decided that was a good idea are a complete IDIOT! and need shooting really! they need their head kicking in!
any way! In the past I have made a feature out of it by sticking a 40mm or so piece of end panel to scribe to the wall and then stick another 40mm or what ever you want at the front but have it set back then stick the dead on size panel on top looks quite nice! BUT you do end up needing to get another end panel to cut up other ways to get around it but CAULK is not the option if its above 5mm [big grin]
JMB