YesTAM,
It's been many years since I've flown an Arrow or used GA aircraft P-Charts. I thought the PA-28*s I flew years ago had P-Charts for the first stage of flap, which I thought was less than 25 degrees. Again, as best I can recall, gravel was considered as sealed, it was only grass which had onerous factors.
Or is my memory just fading with old age?