Hiya Steve,
You'd think your Mayberry's (and spelling variations) were rather well to do having links with Shipping / Mills / Public houses / Durham / London / Jersey. Labourers wouldn't have such links. Have you tried the online directories?
1852 (Directory of Belfast and the Province of Ulster)
There was no one with that surname in Antrim, Ballymena, Ballymoney, Belfast, Carrickfergus, Larne or Lisburn.
I looked in the Village portion of the directory .. that covers Ardoyne, Dunmurry, Greencastle, Whitehouse and Whiteabbey .. none there. Oh! They are annoying me .. There are lots of places not mentioned in the book where they could have been living if they were well to do. It's a great pity there is not a Ros Davies site for
Co. Antrim in the same way as there is for Co. Down.
I looked in the 1960 Directory of Belfast and Northern Ireland .. what do I find? In Belfast .. three Mayberrys repairing boots and shoes. One Maybury living at Barnett's Road in East Belfast (near Stormont) .. that one declined to mention an occupation .. and one Maybury who was a breadserver.
I also looked in Gary Law's Historic Pubs of Belfast .. the surname is not there either.
Chris