You would probably be better getting a joiner as they could competently do both jobs as a locksmith would probably just be able to fix the lock.
(Ps. If you need any assistance with plumbing, Heating or gas works please don't hesitate to ask as this is my field of expertise. Thanks)
We always recomend to post a job on main website because some of a job needs to be seen before any advice is given.
Our service is free of charge with no obligation quote and our tradesmans are happy to help with every aspects of jobs.
I would strongly recomend to post a job on Rated People home page under carpenter cattegory then 3 companies will get in touch then you would be able to choose the right person as you would receive an e mail with a link to tradesman account where you would see a pictures and you will read revious from previous customers.
I hope this will help