Geoff, It depends on what you want out of life. That boat is a fair sized project. If you spend what she needs to make her really nice, you will have way more invested than just buying my 1985 53 ED "Lady Diana" which is near perfect. If you want to take some time and do a lot of the work yourself, and enjoy doing it, then she's perhaps a reasonable buy.
Here are the issues that made my buyer walk-
1. The flybridge deck is full of water. When the boat moved- water poured out of the deck core and INTO the saloon aft port, onto the sofa. It was like Niagara Falls.
2. The engines started right up, smoke cleared quickly, she ran fine- BUT -A mechanic with a boroscope noticed a fair amount of pitting on the liners. This along with the needed full complement of hoses, clamps, etc. Long list of deferred maintenance items including some scary looking wiring.
3. The interior of the boat, the engine rooms, the bilges- all needs a good cleaning. She needs new galley equipment, all soft goods replaced and a general top to bottom detailing.
4. Nav electronics are ancient or non-existent.
The bottom has typical blisters. The paint is decent.
When you start putting $$ numbers next to the projects, the total gets crazy pretty quickly.