hang in there
These W123 coupes are beautiful cars once things are fixed up
definitely check the axles tomorrow sometime for the vibration and also the wheel bearings.
I have never had a front end clunk/thunk. I did in the back and turned out to be a stuck little screw in the lower suspension arm between the arm and the spring (It's 'thrown around' by the spring action). Took the screw out and it was gone.
on the radiator. If the fix doesn't work, try finding a thin copper tube that fits just inside the radiator nipple.
Good luck with the car!