Early American mid-18th C. ladder back rocker

I traded for this rocker 15 years ago from a picker friend. This friend told me the rocker came from a Pennsylvania estate. at the time of the trade I noticed other pieces he had that were from the same group of furniture. I told him that the 3 Hepplewhite backed chairs looked very good. He auctioned the chairs that same year and recieved 5,000.00 for the 3 after Butterfields cuts. I know this rocker comes from a very interesting group of furniture.

I had a friend who was attending a appraisal school here in S. California (San Bernardino). I was told by my friend that her teacher who viewed photos of the rocker, said it was mid 18th C. and was very excited about it.

There is one modern screw unfortunately, it is on the bottom of the front leg by the right skate of the rocker. other then that it looks very original and in very good condition.