If you would, could you go to TVFool.com
type in his exact address and attach the results in a post?
Just typing in the zip code for Harmony, MN (55939), it seems that your brother is 20-35 mi from Rochester/Austin/Mason City stations (all off to the west), 40 miles from Lax's 19/25/31 tower and 55mi from Ch. 8 (off to the NE).
Is it possible you could get us a picture of the antenna he was using before? Also, are there any hills or tree cover around there?
There are two basic solutions - either you could get one antenna (or separate UHF & VHFs) and put them on a rotor. The other solution is to try a UHF antenna on a rotor and aim the VHF antenna straight at WKBT 8, then pick up KTTC off the back.
What exactly will the insurance company cover? One physical antenna or the replacement for the entire antenna system? (antenna, pre-amp, rotor, etc.)
Ideally, I'd try an Antennas Direct 91XG UHF antenna ($53) on a rotor. Then get an Antennacraft Y10-7-13 ($40) below the rotor (make sure you have >3ft spacing between the antennas) aimed at WKBT. Run the two antennas into a Channel Master 7777 Pre-amplifier ($60).
All of the stuff mentioned above is probably cheapest online. I'd suggest a place like SolidSignal.com
For mast, try 2" electrical conduit (available at Menards or the like). It's a lot tougher than TV antenna mast. For cabling, try RG-6 quad shield cable (you can get it by the foot at Home Depot or Lowe's). I like the Palidin Tools compression connectors (available at Menards). You can install them with two pairs of slip-joint pliers.
Also, make sure to install a ground block.
That setup should have signal coming out wazoo!