As you discovered, deobliquing with 3drefit did not make the dataset have only a single sub-brick volume. I recommend you use 3dinfo to look at both the description of the dataset and the history of commands that led to the dataset. It seems likely this dataset is not one that is useful for you, and one of its predecessors is something you are after. As has been pointed out many times on this messageboard, 3dfim+ is an old program that isn't actively maintained. You may be more interested in other programs like 3dDeconvolve, 3dREMLfit or 3dTcorr1D. The output you included shows you are using a version of AFNI that is more than four years old, so you will probably want to upgrade to a recent version.