280GE problems

[usmlm]

I have a 1984 LWB 280GE. The odometer reads 59,000 miles which I assume means at least 159,000. I recently had her inspected by a mechanic who listed the following problems:

- No catalytic converter installed
- freeplay in the left front wheel bearing
- engine oil leak front top cover
- slight leak at transmission
- vibration while driving, suspect front drive shaft problem

Compression test showed the following:
-#1 110 PSI
-#2 100 PSI
-#3 105 PSI
-#4 170 PSI
-#5 160 PSI
-#6 140 PSI

I have several questions. What should the compression be on an engine of this age and miles? Is the varience between compression of 1,2,3 and 4,5,6 a particular problem? Should a valve adjustment me enough to take care of the low compression, if there is low compression, or could I be looking at bigger problems? I have some experience working on motorcycles, and have basic tools but never worked on cars or trucks, let alone a GWagon. I am willing to spend the money to pick up shop manuals on CD, and take the time to do the research I need to take a shot at fixing these problems myself, assuming I can get the parts, but I was hoping someone could give me some idea as to what i could be getting into, am i getting in over my head, and maybe a vague, ballpark guess on how much it might cost. Another challenge is that I have no space in my tiny single car garage to park her while doing work and the carport isn't level.