Help identifying and aging packaged A/C and Electric Furnace

I found this in a condo the other day. There’s no markings on it that show what brand it is. The model number is 15EWC18-8 and the serial number is PMR 3497. Before the serial number, it say “date code” so I think that means it was manufactured in 1997, but I thought most companies did away with stamped metal data tags well before '97. Anyway, figuring out the manufacturer would be good. Dropbox - DSCN1259.JPG

Got a picture?

It’s a Magic Chef and it was manufactured in 1980.

I fixed the link to the picture above.