I filled the gaps with filler and then placed a cut up glove on it which stopped the wooden plug from sticking to it when I squidded it in. Once it had set I just sanded away any excess filler. This idea work really well and I was very pleased with the results.

Iused MDF to make a small plug that gave the right shape for the propellers to sit in.

Underneath where the propellers go had to be cut out then filled again because the CNC machine had cut away to much.

Ihad to sand back the resin as it left brush marks on it and it was uneven in certain areas.

The back of the hull had to be cut out then filled with filler as it showed this on the plans.