The A/C system in my 89 300TE has had a hose disconnected and since it is starting to get warm here in Houston I am thinking it is about time to get it sorted out.

Since it has been open what will I need to replace?

What will need to be done?

Since I don't know what has been done or replaced and everything looks original what should I be replacing?

Also...I will be replacing my heater core and figure since I am going to be doing this I might as well go a bit deeper and replace the evaporator...Would this be recommended? My wagon has 130,000 miles on it.

I basically need to come up with a list of things so I can come up with a game plan and list of things that I will need to be purchasing.