I am no expert on these engines but resorting to basic principles.
1. Your gauge is inaccurate and needs calibrating (although the tests look repeatable there may be an index error).
2. Your 'book' may be incorrect.
3. Your head has been skimmed and an incorrect head gasket fitted raising the compression ratio (unlikely?!).
a. If we take 205psi as a representative test result then you are squeezing at 14:1 whereas your book is indicating you should be at a maximum compression ratio of 12:1.
4. I do not know if you want to continue this out of academic interest or if you really have a performance issue. Normally absolute values are less important than the spread of achieved pressures across the engine. If you do address paras 1 & 2.
Hope this helps - Good luck!
230 TE (W124) 1989 with 153,000 miles on the clock - hoping for at least another 100K