Dear Gang,
Thank you very much for your help!
I got a better understanding for the baseline constant now and finally after including -bout option in 3dDeconvolve I think I have the right subbrick. This time it´s called Run#1Pol#0_Coef (I have only 1 run). When choosing the regression coefficient as overlay, scaling (% mean) compared to scaling after 3dDeconvolve produces similar results. As my baseline constants are near 100 scaling before should be ok.
Beate