Firstly, I've found the names of my 'missing' aunt & uncle, they are Alfred & Lucy. Hank was Arthur's nickname.
Secondly,the mysterious, nomadic William that you have is almost certainly the same one that we have. His 3 eldest children, David, William & Samuel were all born in Pendlebury. He apparently arrived in Cas. with Catherine Townsend & her children William!!, Thomas, John & Paul. William & Catherine had a daughter, Florence, in Whitwood around 1887/88. They lived on the opposite side of Terry's Row to Joseph & family. This fact, together with them both being born in Bilston around the same time led us to believe that they were probably twins. Thank you again for your assistance, Charles.