Hydraulic Press gauge questions

[USMCPMEL]

Has anyone ever calibrated one of these? It is for a hydraulic press. The press manufacturer said it is 2,000 PSI TO 1 ton that seems a bit excessive to me (170,000 PSI full scale). The person I spoke to is in sales and I do not think he knows what he is talking about. We looked up a conversion with the ram diameter (100mm) and came up with about 15,000 PSI. My second issue is I don't have an adapter it is M20x1.5 I need to adapt to either NPT or a high pressure fitting. HIP has the fitting but they want $261. I found ones online for around $20 and below but they have low pressure ratings. I am looking for a source to buy a pressure fitting rated to 15,000 PSI which is what I believe the true full scale of this gauge is. Any help?

[USMCPMEL]

Well we ended up not doing it as we could not find an adapter for it. The customer purchased a new gauge from somewhere that was supposedly already calibrated. I have my doubts.