I spoke to Steel Developments about props and couldn't get past the thick bint on the desk, so didn't have a clue what she was talking about and hence SD never got my Dads trade.
He used Propeller Solutions in Poole who were very helpful and not badly priced.
I think it was £25 per prop for his 16" diameter alloy Volvo ones.
http://www.propellersolutions.co.uk/