After hours of sanding and shaping with many mixes of plaster, Step 4 was to paint the liquid PVA releaser over the 'Plug' for the mould.
Step 5 was to layup fibre glass chopped mat & woven cloth over the plug.
Step 6 (Couple of days later) was to pull the mould off the plug and remove all the clay & plaster off the fuselage, & generally clean up the mess.
The resulting Mould was roughly trimmed and mounted in some framework so that a fairing layup could be accomplised. After as much sanding smooth inside the mould as possible, PVA releaser was applied and
Step 7 was to layup fibreglass into the mould. I used different width tapes chopped mat and woven cloth to build up a thickness of about 1/8 inch all over.