I may be able to help a little here, as I live in Newsham.
1. Railway Terrace is in Blyth, not Newsham and is still there.
2. Railway Cottages are in South Newsham, and are also still there.
3. Charlie Rose is a local character, who I believe is still alive (Or was recently) & still lives in Railway Cottages.
4. Tosson Street is still there. It is situated at the extreme West end of Plessey Road, and is in an area known as New Delaval. Although it only contains 1 house, which is the end of a terrace on Plessey Road.
5. The signal box (Formerly Newsham South), is still opertional and called Newsham. It stands guard over the level crossing on the A1061 South Newsham Road, and controls all the level crossings / junction & signals in Newsham.
I hope that helps.