Easy One for all you Draftsmen: Mechanical Drawing Interpretation
I agree with Twirly- if at all possible, check with your customer.
'Course, if it isn't possible:
My take is that they asked for Alloy 600 per ASTM B166, cold drawn, but not to exceed HRC 35. Fine- sounds like they want to use it in a downhole application, since NACE MR0175 often has a HRC 35 max. If your material meets those requirements, then I would say you're proceeding acceptably.