Since Mary Abrell and John Mead were married in 1726/7, I assume she was born around 1700-1705 and her father would have been born around 1670-80. If Richard died in 1750, he couldn't have been born much before 1670. If there is any relation between this Richard Abrall/Abrahall and Richard or Robert Abrahall in the 1650s, then one or the other could have been his father, or even grandfather, since both must have been born in around 1630 or before.
There are lots of ifs in that paragraph. I don't suppose there were as many Richard Abrahalls as William Meads. I have tried to sort them out and there were at least half a dozen William Meads in PA and MD between 1680 and 1720. The earliest reference I have found was from 1681, when William Mead and some two dozen others wrote a petition complaining about the “rude, imperious and insolent behaviour” of Edward Inglish, sheriff of Cecil County. This William Mead must have been born before 1660, so he could have been either the father or grandfather of John Mead.