First off, the good news. You've got a rather valuable guitar on your hands. A quick perusal of Gbase puts a clean 000-18 scalloped braced, red spruce top and original finish at around $10,000.
Given that, it's definitely, absolutely worth having all the work done and done right.
The work you suggest is almost routine maintenance for a guitar of this vintage, and even if the bridge needs to be replaced, if it's done with a perfect modern bridge (i.e. a forgery grade copy of which the best luthiers are capable) there's no hit on value at all.
If you were in the U.S. I could suggest a dozen luthiers who could do the work on a vintage Martin. I'm sure there are a few guys in the UK who can do the same quality work, but I don't know who they are. I would post on the Vintage Corner of the Unofficial Martin Guitar Forum, and ask for suggestions. (Nice guys and very helpful, much like TDPRI)
One caveat. Just as you wouldn't bring an old Aston Martin to the same garage that works on your new Ford Escort, you should be very careful about choosing your luthier.
Many luthiers are anxious to get some experience on an old Martin, but you don't want a guy cutting his teeth on your guitar.
Good luck, and post some pics when you can