Nice FJ55. I still like the two color paint scheme as it really looks good on that model .It looks good single , but I believe it will attract more people to two tone.
To me a vacuum gauge is to pressure as a multimeter is to electricity. You can see small changes that without it , you would never know. I will be interested on this as I am restoring a 1965 LPB with a rebuilt SD40. Not as far along as you.
I am glad you realize that. As things age there is always someone who wants/needs original parts for a restoration. I believe a while back a crate engine, NOS, a Ford 427 from the 1960s , sold for 75K. Some FJ40 parts NOS are quite a bit more than original right now.
I really cannot tell fully but that tube is solidly attached to the frame. Whatever happened there one would assume the frame itself has been affected as well. I would not feel good without putting in a new tube and measuring the frame to be in tolerance. There are frame shops that can do this.