GP 35x series repairer

[Bluestifford]

Hello

could someone please tell me where In the UK I can get my GP 352 serviced I want someone au fait with this calibre . I have a few of these in running condition and one had a stem come out so I thought I’d like it serviced and cleaned as the date mechanism is a little sticky at times. 
Thanks. 

[transporter]

any watchsmith worth his salt will be able to sort that out for you mate