Regarding your release problems; you could try getting some water between the mould and moulding.. Get a hose in there if you can.
It will help soften the release agent and the weight of it will help push them apart.
They used to crack off a bit of the top of a boat hull moulding (up to 80' boats!) and push a hosepipe in there, running for an hour or so. If you were lucky, after a while the buoyancy of the moulding would overcome the stiction with a crackle and the moulding would be floating an inch or two out of the mould.
The ye har method was to lift the moulding via temporary bonded in eyes, with a giant crane. it would be hung a foot or so from the ground and jerked a few times. (Very scary as the crane wobbled on it's jacks!)
Release was heralded by a mighty crack and often a brilliant flash, even visible in daylight, as the static charge dissipated, then a thump as the mould hit the ground.
Killjoys could avert the static flash by laying a chain over the mould's metal framework to contact the ground, but a sort of sensible approach really, if the releasing is done inside with all that styrene and acetone about.
You could also try beating your moulding about a bit with a rubber mallet. An excellent way to decorate your moulding with ornate star crazing...
