Unless you want to use the antenna for FM as well as TV reception, you have no need for the big, bad 8200 since there are no TV stations to speak of on channels 2-6 in your area. Winegard's equivalent 7-69 model is the
HD-7698P, but you don't need quite that much gain, either.
A "slight" bend in the reflector by itself wouldn't kill reception of all but your two strongest stations. As long as the bowties aren't touching the screen or the boom anywhere, and the balun is connected properly to both terminals, the antenna isn't the problem.
Let's start with the basics:
• You are using RG-6 coaxial cable, right? RG-59 coax can be used, but loses much more signal than RG-6. (The cable type should be stamped on the outer jacket in contrasting ink.) Any other type of wire is totally unsuitable for over-the-air reception.
• Perhaps the cable has a poorly attached F-connector somewhere, or maybe it sustained internal damage when it was installed. Coax can be damaged by yanking it hard through a hole, for example. Check for obvious signs of injury or stress. Permanent kinks, dents or bulges are bad news.
A Winegard
HD-7696P would be more than sufficient with those signal strengths if you really want to swap out the 4228, but my hunch is that a new antenna won't resolve this issue. That 4228 iteration was a peerless antenna. It really sounds like it's either a short or broken conductor, faults that usually crop up in the downlead cable. If you're certain everything is in good working order, I'd install a pre-amp before putting up a different antenna. You may just need to overcome loss in the cable, and that would do the trick.