Aldgate sits in East London and offers much to do including musical instrument shops. Some of the best shops in the Aldgate area are:
Andy Baxter Bass & Guitars Ltd: This is a vintage bass and guitar shop in London. This shop has established itself as the best place to find vintage basses in the UK. They are also a name in the vintage 6 string electric & acoustic guitar area. If you need a Gibson for a friend, this might be the place to find one, and at a reasonable price.
If you don’t have any luck in a guitar shop, why not go to a resale site such as craigslist or gumtree to find a guitar in good shape at a decent price.
If not online, most shops that you go to will have guitars for resale available.