1992 745 Help diagnosing blown head gasket..

[Crispy]

Grandma's '92 745 w/ 150k came to me in 2004. I had been experiencing high crankcase pressure last year and found a clogged air box and flame trap. I then had a replacement blow apart at the seam. At that time, I did the dancing oil cap and tried to access if I had excessive pressure in the crankcase. It seemed better after the second air separator box and drilled out flame trap. Fast forward 1 year of not driving the car much and fighting a couple other problems. Recently, I noticed the o-ring on my dip stick was broken so I wrapped it with teflon tape. Yesterday, after getting home from an 80 mile round trip, coolant and steam was leaking from the rear passenger corner where the head meets the block. My oil cap does a little more than a dance now when you loosen it and observe the crankcase pressure. No water in the oil or oil in the water but there is a little bit of a black film inside the coolant reservoir.
So... fixing the dipstick may have increased the crankcase pressure enough to pass the problem on to the head gasket but I have a question.

What's causing my present high crankcase pressure? Could I have had a blown head gasket for the last 1-2 years causing my new breather box to blow apart, my dipstick to blow out of its tube and now a coolant passage leak on an outside corner of the head gasket and NOT have seen oil in the water or water in the oil?
Or... With 150k, could my rings be so gone that the pressure is this high?

This car was Grandma's and has always been in the family and she had it serviced. Oil changes have been neglected a little in the last 10 years but it doesn't get driven much.

If it's rings, I'll probably junk it but I don't want to. I'm thinking I should replace the head gasket and access but I don't want to waste time and $.

Could I have had a blown head gasket just enough to have a good running car but high crankcase pressure with no other head gasket symptoms like contaminated water or oil?

Thanks in advance, C.

[Crispy]

Bought a head set and will do the HG. C.

[93Regina]

Bought a head set and will do the HG. C.

Read the manual...there is a correct procedure to remove and install head bolts.

[lummert]

Bought a head set and will do the HG. C.

Read the manual...there is a correct procedure to remove and install head bolts.

Yes, remove those bolts in the correct order. If not, you take a chance of warping the head.