[Unclenick]

Sounds like it was rubbing along the underside of the step. Sometimes that part of the step needs to be filed from the bottom up to thin the extension. Painting it with Magic Marker and reassembling will reveal where scraping occurs.

The grip safety, AFAIK, is just intended to prevent the trigger from striking the disconnector hard enough to move the sear off the hammer should you drop the gun muzzle-up with the thumb safety off. If you stay in the habit of pushing the thumb safety up every time you are not on a target, the lack of a grip safety will be of no consequence. Just don't sell it in that condition, as the liability could come back to bite you.