Re Thomas Mason to Eliza Sivill marriage, you could check the birth of one of the children for mother's maiden name. Strangely enough the only clear one is Mary Jane Mason - June 1873, Macclesfield 8a/155.
There is an Eliza Sivill b Broxton way
1851 HO107/2171/12/17
George Sivill 38 ag lab b Bickerton
Sarah 28 b Bickerton
Eliza 6 b Bickerton
Charles 4 b Broxton
Hilary 3 b Broxton
John 7 mths b Broxton
I'm going to leave it there for now, let you catch up and fill in a family tree.
If you need any more get back to us, and I'm sure anyone will be pleased to help. Happy sleuthing!!