Thanks for your input regarding the PVA and wax release agents, guys, and before I take any more mouldings I'll be testing different techniques out before using it on the mould.
And thanks for your kind words Oxford and Paul. If you'd told me ten years ago that I would be fabricating such a complex part in fibreglass and achieving the result I have I'd have thought it impossible.
But then I searched 'Spyder' on ebay hoping to find a 718 RSK project or abandoned kit, but came across Gary Jaynes' Sammio project instead.
Since then I've learned skills like welding, making my own moulds for complex fibreglass parts and spray painting to a standard that looks quite satisfactory. Well, satisfactory enough for a serious car collector to fall in love with one of my cars and display it amongst his selection of classic Ferrari's, anyway.
So, next step is to bond the new dash into the body, blend a fibreglass bulkhead I have managed to acquire into the body and dash, then fabricate and bond in a complete floor in fibreglass to pull it all together and give the body the strength it needs.
That sounds like it shouldn't take long...