Thanks Kajtec, exactly what I thought and did. Nice that you confirmed it.

 

I installed the Basket, it has 3 holes to fasten to the engine but only 2 holes match no matter how one turns. After that I removed the center bolt. I have all kinds of printed out data still from the last time I did it, there was no problem then.
I worked all morning to make it go without success. There is nothing around the pump that could impair the process. the problem must somehow be internally. The 3/8" clearance that is showing is evenly all around. I hate to apply brute force for good reason. Thanks for coming back to me and wish that you or someone else reading this has an answer.

 

It is few years since last time I was pulling IP out, but you should see the pump shaft coming out of sprocket assy on the front?
If I remember it right, the assy is called "timing device"
You might want to google the name and check W124 sites as well as older pumps had the same design.