Based on the trim that I can see in the opics, I would judge it to be a early to mid 70's hull.
To redo the transom is a big job, but if done will add at least a thousand to the value IMHO
The motor is probably worth 700 - 1500- it's old and a fuel hog.
The trailer would be worth ~500 on a good day - ownership is easy just re-register as a home-built.
This paticular hull is very sought-after as it is proven to be one of the best big-water hulls out there. And the fact that it is setup for an outboard is an advantage as a lot of them were I/O. It is much easier to upgrade your powertrain if it is an out board.
I have seen these for as little as $300 and as much as $9000 when I was looking for the bow rider version of this hull. I would be tempted to take on another project, but...