Jack, Having restored mine from the brink here are a few pointers:
There are manuals available which are a must, read the relevant section before you start. There is also a 'Guide to Restoration' the title of which eludes me for the moment. These are available through the Club shop, along with some mechanical parts and as far as suppliers I found Canley Classics (good website with lots of extra info) and James Paddock my preferred people for most things, Fitchetts for panels.
Mechanical stuff is not the issue, just requires a bank balance plus a degree of skill which improves with time/skinned knuckles plus questions on here.
Bodywork is the defining factor and yours looks to tick most of the boxes: bonnet, sills, screen frame but most particularly the roof. Panels are available but there is more to it than that, not least alignment.
If it is made by a man it can be repaired by a man but you have to be realistic; however, if there is a emotional attachment then that overrides most things. Whereabouts are you because I am sure your, assuming you are a member, local TSSC group would come and give it a closer look and provide advice.
Dick
ps and reinforce Mike's comment about taking photos before you start!