UPDATE:
I ordered that new housing thingy last winter. My channels were coming in fine after my last post, so the housing sat in its shipping box.
So here it is in late June and channel 8 is still coming in fine (I always lose 31 in May). As it is now, everything is normal and as expected, yet I've done nothing to the antenna, preamp, and the new housing has not been installed.
All of my equipment is the same as it was last December when 8 was giving me huge problems. So what was actually causing the reception problems, something atmospheric? (sunspots or something?)
TIA for your comments!