Please take a look at engine parameters in compare tool and variant comparison (engine design screen). They are still inconsistent. The thrust of my older jet engines increased again when I started to design a new turbofan generation of engines. I know that for sure since I typed thrust in the engine names specifically to check if this takes place. It seems the designed engines account for jet engine efficiency increase as years go by, or something similar. And they suppose to stay static.
You can try to design some new engines in the save I sent earlier. I name the engine something like 55CTJ57-30, where the last number (30) is the thrust at 0 altitude. This particular engine gave around 30000N of thrust in 1955 when it was designed. Now I design a similar turbofan engine in 1962, and when I compare the new engine with that one, it shows thrust around 32000N for some reason
I'm going to check if other values are affected as well