When Wilf brings a TV aerial to fit to the Larkins' house, it is a modern UHF aerial - a series of bars of varying lengths arranged along a central spine. In the 1950s, the 405-line TV system used VHF and hence a much larger H- or X-shaped aerial, or a combination of the two.
When Pop and Ma arrive at the hotel in Margate, the doorman welcomes them to the Margate Grand (its fictitious name in the episode). However there are several very prominent signs showing the hotel's real name, Walpole Bay Hotel; also the hotel's logo WBH is visible at the reception desk.
The prices in Wilf's shop are decimal not £SD - the TV for sale is priced at £15.00 - it would more likely have been priced as £15-0-0 or possibly even priced in guineas - but don't let these quibbles detract from what is a very good series.
The beach is supposed to be Margate but is quite clearly Broadstairs.