First of all I made a cast from wood in the shape that I needed and purchased a fibre glass kit from fibreglasssupplies online.
I didn't know what to use a release agent and I had read on the forum that simple cling film would do the job.
Well it might do but not when you are using a gel coat. It was a complete cow to get the gel coat on, and I had to use some off cuts of fibre glass to hold it to shape whilst the gel set.
The actual fibre glass bit was fairly easy and everything was dry in a couple of hours. It released from the mould ok but then I needed to sand off the cling film and P38 up the mould to tidy it up.
It fits pretty well and also provides something for me to mount the wash wipe relays and the fuses for the dash on. It should also keep Mr IVA happy and should fine once carpeted.