MXS C-15 Oil Pressure and Temperture

Was just curious what the oil temp and pressure should be on my MXS Acert. My oil temp seems to run in the 200-220 range. This is with coolant temp at 190-200. Seems too hot to me. Also concerned with my oil pressure. Only around 15psi at idle when the oil is at 200 degrees at 600 RPMs.. Runs in the 40-50 range while driving. First I would like to put in a manual gauge and confirm that it is that low. New to me truck that I changed oil in before I started using. This is in a 2006 KW W900. Some questions?

What is normal hot oil pressure at idle?
Is my oil temp higher than normal?
Where do I put a manual gauge in to check oil pressure?
If it is that low, where do I start checking for problems?

 

I checked my oil pressure with manual gauge, and the dash is accurate. Now where to start looking for the cause of my low oil pressure??

 

Talked to one guy that said the oil regulator or bypass valve in the oil filter housing is a cheap place to start. Make sense?

How do you go about cleaning the oil cooler?

 

Not sure if it makes a difference but this truck pretty much sat for almost 2 years. Has 830,000 on it. Changed the oil before I started using it and took an oil sample. They said everything looked fine for an Acert except that the iron was very high, but said that sitting for that long could have caused that. No idea the age or condition of the oil that was in it

 

The few places I talked to last week were telling me that 15 psi is still in spec and don't worry. I have to think that if 30-40 psi at idle is normal that 15 is unacceptable. What do you guys think?