So finally today I got to the bits and pieces and put it all together. Talk about taking time. The pressure relief valve kicks in at 45PSI for some reason so will consider replacing this maybe. I found that one of the cast right angles that came with the pot actually has a very small crack which releases a small amount of air.
So now to find where to source measuring cups, release agent, and some HPE to make some molds.
The journey has got underway!