Thanks for the feedback guys,

After reading your replies, I searched online for NAK55 and DH2F. I
will also check into the Viscount.

I read something about one of the grades in a "hi hard" condition of
45/48 RC, which would probably have a high compressive yield strength
in that hardness. At about what point in general would a pre-hard
steel be too hard to really machine effectively ?

Can you recommend any online sources or books that have compressive
yield strengths for these materials in their pre-hard state ? So far,
I have not found much. Can you recommend any sources of supply for
small prototype quantities ?

Thanks again guys,
John