Thank you for the help and advise and the links.
I'm thinking of staying at the Ibis Budget in Chinatown. I did check the Premier Inn but it's significantly more expensive. Ideally, I'd prefer a homey B and B instead of an impersonal hotel but I haven't found one close enough to the station around the same price as the Ibis Budget.
My grandfather was a Londoner, he passed away about 20 years ago. I have some memories of him when I was a child talking about travelling to factories and corporate offices in Manchester and Birmingham. I have no clue which factories and offices he'd visit. He used to export British products mainly sweets, chocolates, snack food and medication. I'm guessing he would have had some contacts at Cadbury's. I think he was also working with Pascal Sweets, but that brand name appears to be obsolete now.
I plan on arriving in the evening on Sunday and spending Monday and the early part of Tuesday in the city. Ideally, I would have left on Tuesday morning but some sights (mainly Back to Backs and museums will be closed Monday). I did plan on visiting the Jewlery Quarter Museum and Back to Backs on the Tuesday.