To build or not to build (meaning sell)
Nobody can answer this but you.... You have the skills so that's not a road block. Time and money. Maybe you need this type of project in your life since you can do the work. Any of this cost money. And truth be told if someone could add up all the hours to restore something like this they would be better off working part-time at Wendy's and something further along and be ahead.
I let a car go in the early 2000's and was in worse shape. I regret it as it had the bones for a big return if I ever sold it and was crazy rare. Today no way would I touch something like that. I would save up, write the check, and find a car that didn't need that type of work.
In the end it's all about you....