What time is it? Watches and horology

Alsal watches would get my vote, they normally seem to be able to help with the basics and are a safe pair of hands.

Does anybody have any recommendations for a service to replace crystals? I'd like to replace the crystal in the Seiko that I dropped yesterday, have a 1960s childrens watch of unknown make that I'd like to fit a new crystal to and was thinking about getting a domed crystal fitted to my Helson Sharkdiver if possible.

Would happily recommend little yellow shop in Clerkenwell, prop John... about GDP 20