Armstrong flute- I want to figure out when it was made?

[ActuallyACellist]

So for a recent birthday, my sister got me a flute from some guy on craigslist. None of us know anything about the instrument. The serial number is 13045. Engraved just below where the head joint attaches, it says W. T. ARMSTRONG/ELKHART-IND/104/30/13045. on the internet, I could only find information about serial numbers 18000 or above, so I'm not quite sure what to do with this number. I like to know when my instruments were made, and I know nothing about flutes, so if someone could help me, that would be great! Thanks!!

[pied_piper]

Your flute was made in 1980. That is determined by the "30" prefix to the serial number. From 1974 to present - The prefix number plus 50 will give you the date manufactured. So, 30 + 50 = 80 (1980).

[cmitca]

Hello
I am renewing my desire to play the flute.
My mother gave me this flute as a gift in 1976. How may I find out more about my flute, such as when it was made?

The middle section front near the top indicates:
W.T. Armstrong
Elkhart-IND
There is a sun like logo
90
8 106

The back indicates:
Sterling body and
Head only

I could not find another serial number.

Thank you!

[pied_piper]

90 = Armstrong Model 90 Sterling silver body/head flute w/closed holes
8 106 = serial number

Prefix 3 thru 9 was manufactured in 1973

I hope that helps.