Crashly

A few days ago I bought my friends 77 Targa ($5k). It had bee sitting for a few years so I towed it home, and started searching Rennlist about how to get it started. The next day after cleaning all of the ignition pins on the wiring and draing the gas it fired right up!!It idkes nicely. I knew about all of the problems with the 2.7 before I bought it and fortunately my friend had taken it to a shop here in San Diego called Volkers and had a lot of work done. He had them install a front fender oil cooler and some SSi headers etc etc . I believe that it already had the 11 blade fan when he bought it along with the updated hydraulic tensioners. I need to do a valve adjustment so I have a few questions maybe a few of the gurus here can educate me on. Fortunately my friend did maintain the car, however he was not a motor head. He would simply drop it off at the shop and return later and hand them few thousand dollars. I have tried talking with him to get the maintaince records but to no avail. The car sat a lot while he owned it as he was constantly deployed overseas for a few years at a time and when he was here in the US he had a few different cars that he drove. So I am trying to determine the overall condition of the 2.7. I plan on doing a compression check after I adjust the valves, then I wil do a leak down test. The car has roughly 125K on the odometer. From what I have read in a few books and forums it seems like the 2.7 never made it over 60 K without major work (valve guides, head studs etc). When I do the valve adjust I was hoping to do a little detective work. If any of you can help me out with any advice please pass it on.
1. How do I tell if the head studs Have been replaced. magnetic vs non magnetic??? good bad??? Divilar, raceware etc?
2. Is there any way to determine if the valve guides have been replaced? Drill tooling marks? different colors of guides?
3. I have heard that there are good valve guide seals and bad valve guide seals. Which are which?