I would like to know how old my dryer is. It's an avocado green G.E. Versatronic Control Dryer.
Model Number 820 D1 A
Serial Number ZC212 579

I'm thinking it must be early 70s and it still works great! I don't have the manual, the dryer came with the house.

Look at this: https://dl.dropbox.com/u/8010163/Appliance_Date_Finder.pdf You still should tear it down and clean it very well and grease the bearings and replace the belt. That dryer is one of the old "house-burner" dryers, I believe. If not cleaned yearly the old dryers were good to burn down a house. I bet it has already been burning lint deposits for it not to have stopped by now to be cleaned. Newer dryers would have burned out a safety by now until cleaned and the safety replaced. You should clean it out well without delay. Look at these, too: https://dl.dropbox.com/u/8010163/GE%20Dryer%20%20Manuals.zip