factory air con was available from about 85 but that looks like it was an after market set up
what you eed to do is figure out how to get the fan working first, as that's where the problems will occur
plumbing wise you just have to hook up the pipes to the matrix, if you are going to get the dash out it's probably best to check to see if the matrix needs replacing as sitting around with nothing it it may have killed the cores and as soon as you hook it up it will pipp water out into the footwell