Hi there Alsonso
Looking at the picture of the moulds which you have put on the forum, I first thought they came from an injection-mould setup, but, you would have had the inner to go along with the exterior moulds as well.
What made me think this is - it looks as though, around the flanges you have what appear to be locating slots on the moulds. These would be fitted into a cradle, then fibre glass matting would have been placed into the bottom half of the mould. The internal mould would then have been placed on top. Then, the whole unit would have been placed into a press, where the resin and hardening mixture would have been injected in. With you not yet having a photograph on the forum I am unable to tell if this is an injection mould. Very much doubt it is though.
As far as looking for someone who is capable of producing good castings from these moulds, and bearing in mind the rarity of them - the only person I myself would trust and who has insurpassable experience and knowledge in fibre glassing I would recommend a gentleman named Robin Whitmarsh from Kingston Mouldings - and this is the link -
http://www.kingstonmouldings.com/home.htm - so you should contact him. Hopefully, he will be very sympathetic in the rarety of these moulds - should be able to advise you/put you in touch with someone who can help.
aye
john