Welcome back to Ohio and OFCC!
You won't be able to just hand over your PA permit and get an Ohio CHL - but you may not need to re-take the class (however you will be required to reread the OH AG Pamphlet).
If you still have your old, expired license then there should be no problem *renewing* your OH license. Fill out paperwork, pay fee (which likely will be higher than the usual $50 renewal fee since you've not been an Ohio resident for the past few years) and they should issue the license.
Even without your old license, you *may* be able to renew. The law doesn't require it, so you legally should be able to renew without it, it depends on the Sheriff and how much you are willing to fight. Personally, I'd be tempted to go to Wayne County instead of Stark. They tend to be much more friendly toward concealed carriers.