Hello VYSK and Michael W,
Thank you for your suggestions.
I first checked the ground glass and Fresnel, they where assembled in the right order and I cleaned them just in case. There was no improvement in sharpness.
Just to make sure that the assembly was right: Hood, ground glass, Fresnel (with the milky side and ribbed side facing towards each other) bellows and lens.
Then I tried to measure the lenght of a certain point of the front end of the camera to the ground glass (image-1) and did the same on the dark slide of the mounted the PA-145 (image-2).
There is one millimeter difference but when the darkslide is removed the distance became the same. It was a bit of a crude measurement but it was all I could do at this moment.
So alas no solution at this point. Any suggestions are welcome.
Thanks for your help!