That's a tough question. I looked at all the photos and it made me sad --- as you already know, there's extensive rust damage "everywhere" the eye can see. The really hard part is judging whether or not it would be "worth it". I know that cars in worse condition than this one have been successfully restored. It's not easy, and it's certainly not inexpensive, but given the will, the time, the effort, and the cash - it's possible. You'd spend "a lot". Unless there's something about the car that makes it very unusual, rare, or desirable you'd probably spend at least two or three times the amount of money you could ever hope sell it for.
But then there's the fact that it's your Dad's car and with him being the original owner... well it's hard to place any kind of value on that. Depending on your situation, just that fact alone could make bringing it back "worth it" to you personally and then some.
That's up to you do decide.
I wish you success and peace with whatever you decide to do.