Hmmmm.... Hate to say this, but don't get your hopes up.
Your TVfool plot suggests you're likely going to need a lot more antenna along with a pre-amp and, probably, a custom channel 43 notch filter. However, since you already have the C2V, use a TEMPORARY [emphasis added] mount and put it up on the roof and retest. It will be interesting to see what happens.
Tech support for Antennas Direct