I would hesitate to give a number for the point-spread function for each of the scanners. The PSF will be dependent on the reconstruction used, so it would be more of an effective PSF. What I could provide is either or both of the following:
1. The effective resolution of each scan given the reconstruction parameters used at that site.
2. The amount of smoothing we apply to the scans to achieve an effective resolution of 8 mm FWHM.
If you would e-mail me (koeppe@umich.edu) with more details with what you are wanting to do with the PSF, I may be able to be more helpful.