Try with HAAS TM1 or HAAS ofice mill.
This is not an easy job as it seems expecialy if the tools need a close tolerance and if they need to be exployted for long series of parts. To achive a great tolerance try to mill finish small chip of the die after heat treatment(you can find tools for that type of miling at SANDVIC or try with SARTORIUS, i use sartorius tools) Try to use 4226 material ISO standard(or OCR12)
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