[tomfoolery]

Since you have access to the attic, and plan on going up there anyway, consider mounting something with substantial gain and directionality up there. Like an HBU33 or HBU44, which is designed for both UHF and high-VHF.

I'm using a DB4e in my attic with a single dipole for high-VHF (left over from a portable tv) combined into a single RG-6 using a UVSJ, but my signals are line-of-sight (LOS), physically closer, and about 10 dB stronger across the board than your report shows, plus my roof looks right at the towers and doesn't have metal or wiring in it, so attenuation and confusion isn't as bad as it could be with other construction types.

An attic is far from a great place for an antenna, with signals bouncing around in there, but it's likely better than attempting to look through a myriad of interior walls and appliances and wiring and such. With your transmitters in a tight group, a highly directional antenna with good rejection off the back is what I would think you need in there.

But you said you get some stations with a cheap rabbit ears with UHF loop, which is promising. The signals you're getting cleanly are all through that small UHF loop. Have you tried laying the VHF dipole (rabbit ears) elements out flat, perpendicular to the direction of the towers, and set to about 32" wide total length (roughly half-wave length of channel 7)?

There are pretty good indoor antennas, too, like the Terk HDTVi (non-amplified), but the VHF portion is still a single dipole, so if you're not getting VHF signals with your present rabbit ears, I don't think improving UHF alone is going to make you happy.

I experimented with a similar rabbit ears unit in my attic before putting a larger outdoor antenna up there (huge improvement over ground floor), so I might also suggest setting the rabbit ears to 32" and trying it in the attic. Single cable to one TV, no splitters. It's free to try, so why not? If successful, consider an outdoor antenna, particularly one that's easy to fold back up if you want to take it back out, which the Antennacraft units are (IMO).