Tried to start the bird after a couple months of sitting and at first it started to turn but never started and then it just started to click repeatedly. I tried starting it several times after that and eventually it was just clicking and wouldn't even turn.
I have a 428 in my 68 bird which was fully restored last year for what it's worth. Back before this problem arose, I would have to have the car in neutral for it to start. So I know there was a neutral safety switch issue. I tested to battery and that is fine.
I am thinking now it could be the starter but could a the neutral safety switch be the issue?
Sounds like a weak battery, try a known good one. If no luck, I wouldn't think it's the safety switch or the starter wouldn't click. I'd remove the battery cables, clean the battery posts, ground bolt, the terminal on the starter, both ends of the cables then reinstall and try again.