Any info on my central air conditioner model

by Mike
(Brogue, PA)

I just bought my home a few months ago and thought I should have the central ac checked before I started using it this summer.

The house has electric baseboard heat and central ac. The inside unit upstairs in the attic above the garage says its a York unit model MCB42-6A and it looks pretty old. The outside unit is a Goodman and is a 3.5 ton unit.

I did a search for the Goodman unit and found the info for that piece but I can't seem to find anything when I search for the York unit.

How old is this unit, what is its life expectancy and if I was were to replace it could I had heating as well as ac, and if so what would I need?