I got the idea when I was hanging around Travin's shop, they were making some moulds for me

They do two small machines, both close the mould with a glorified G clamp, no ejectors. One air driven, the other using a lever.

They used to do the Travin Eagle which was a fully automatic, air driven, hot pot moulder but they seem to have discontinued it. They usually had one running and it seemed to work well.

http://www.travin.co.uk