[GreenKeys] Determining the age of a Model 15-KSR

[Corey Anderson]

Greetings GreenKeys list readers,

I've been lurking on the list for a few years, and was wondering if its possible to determine
the manufacture year of a Model 15-KSR by serial #. I realize that they were produced for 33 years which
is incredible. I picked one up today to add to my collection, and it's in such amazing
shape that I can't help believe it is either a later model, or could be older and simply 
received little to no use.  I haven't seen (or noticed) anyone discuss this, and a search through
my email was fruitless. Any help would be appreciated.

Corey
KG7UX