sudee,
Newcastle Central library has a large holding of ERs for Newcastle and a handful of others, such as Wansbeck and "Tyneside".
Willington Quay and Howden areas were not part of Newcastle.
I can tell you it is a pain looking for ERs for the area that is now termed "North Tyneside".
North Shields library has the largest holding, but several years and areas are missing. Other libraries, such as Wallsend have no "old" ERs.
Additionally Northumberland County Record Office at Woodhorn has a range of ERs for parts of Northumberland that are now North Tyneside.
Michael