I also live in PA.
Consider removing as much dead grass as possible (a dethatching machine will do wonders and will save you back breaking work with a rake). Do the entire lawn but concentrate on the dead areas. Run your lawn mower and bag up the dead stuff as much as possible. It will be dusty work.
Spread a light to medium coat of sand over the lawn and then aerate your lawn. This is very good for poor soil that has a high clay content.
You can either rent an aerator & dethatcher or hire someone to do it.
After aerating generously fertilize your lawn with a good soil treatment that won’t burn, such as Milorganite. Top seed the entire lawn, especially dead areas.
Spread peat moss over the top, as much as you can manage/afford. Water well. Peat moss will work like hay to help your seeds grow but will also help your soil down the road. It will look worse until it looks better.
Don’t worry about weeds. Anything green is OK at this point. Once the grass is well established (a couple of months or so) use weed & feed. Spot seed where needed.
By fall you’ll be glad you did. By Spring you’ll be very happy.
Excellent advice on the Milorganite and the peat. :)
I'm familiar with aerating and using peat moss and will continue their use/application. The one thing you mentioned that I'm not sure about is the application of sand. Frankly, I'm not sure about the composition of my pathetic 'top-soil'. Is it mostly clay? I'll need to test. I do know that the 'top-soil' layer is 6" deep maximum and below it is shale.
Thanks you for your suggestions!