ventilation woes--yearly differences?

[glassman]

Having read the threads I could find on diagnosing my climate problems, it seems that most posters are talking about later cars than my new '79 300td. I know the console controls are different, but are the guts behind the dash/console also different?
Would controls from a later car work in mine?
Are the ACC servos and Vacuum pods different in '79 and later cars?

Please advise a dumb newbie . Thanks, Glassman