I've been stalking a friends Porsche that he's had in storage for years. He finally knuckled under to the pressure

and is ready to sell. I went to the storage unit a couple of weekends ago to look at it. The storage is a high elevation, low humidity environment.
It's a 1973.5 911T (CIS) non-sunroof in Tangerine. It has been in storage for 18 years. The paint is immaculate and appears to be all original, zero rust (even the battery boxes). The engine compartment is clean, updated tensioners, although it appears to have some oil leaks from the bottom end. The interior is excellent, no cracks in the dash or rear parcel shelf, but the headliner has some staining (which I find curious) and will need to be replaced. I sniffed the fuel tank and surprisingly it smells exactly like gas should smell, although I have no illusions on this and am assuming the whole fuel system, from tank to injectors will need some level of attention. The mice have been lurking in and around it, but there is little to no damage. I checked as much of the wiring harness as possible and found no munching.
I'm no newb to Porsche's, I currently own a '78 SC. I'm capable, and willing of doing all the work myself, except maybe the fuel system. I have a $ value in mind, as well as a $ budget in mind for what it would take to get it road worthy again, but feedback from this forum would be appreciated.
Thoughts?