Guest,
Your channels 5 and 6 have relatively low-power output @ 10kW and 19kW. Before the analog-to-digital transition my local channels 4 and 5 were full-power stations @ 100 kW and their receivable range maxed around 80 miles: there were exceptions. If you go back to your antenna survey and click on the channels, it will show you an estimate of the terrain between you and the transmitters and there appears to be a tall hill or mountain "in the way" - but enough of the signals may refract downward to be received.
Unlike UHF and VHF-hi-band, low-band VHF reception is more easily disrupted by electrical interference such as a 'noisy' fluorescent light balun, your electric shaver, kitchen appliances etc. That said, the cost of building a loop antenna is minimal and I would try it. This is a situation where an antenna pre-amplifier may be beneficial, but try it without an amp, first.
All attic antennas are affected by metallic objects to some extent, so try to mount it away from any HVAC ducting or steel chimney piping. If you have metal siding on your house, all bets are off. However, since its a 'flat' antenna it could be mounted on the outside wall of your home and painted to match your siding.
Please report back with your results.
Jim