The entire dish, if using the original matched LNB, needs to be skewed 23 to 27 degrees depending where you are in Massachusetts. Even with the correct skew it will be hard to get every transponder because the dish is only 24" tall.
Actually, elliptical dishes with MATCHing Feedhorns, operate more closely to the width of said dish, not height.
Of course if you put a round feed on it, then you have a problem, everything else being equal.
And while you can't guarantee 100% accuracy of every transponder on those maps, they certainly show a trend. :up
Eliptical dishes are always skewed to their bird.
Markings on backside of dish usually show 90• as "upright".
I have confidence that with a dish tweak, as described above in post 19 by Brian of SatelliteAV, reception will be restored.