Just be aware that these rifles are the last of the breed that were 'hand made' & 'hand fitted'.
'Fitting' new wood means exactly that - it will require some FITTING, they are not 'plug and play' so be prepared to do some minor surgery.
I spent hours and hours trying to fit a 'pre-used' forend to a barrelled action I had and just could not get it working, the bolt would not cock.
I removed the forend from another rifle and tried that on the Barrelled action and it worked OK, I then tried the original forend on the rifle from which I had just removed the forend to go onto the barrelled action, and, with a slight shaving it fitted and worked perfectly.
Every No1 MkIII is different.