Looking for feedback on serial number. Doesn't seem to match with serial numbers posted on Conn-Selmer website. Any thoughts?

<Added>

I'm looking at purchasing a vintage Armstrong professional flute with a serial number of 190 6 6092 according to seller. This doesn't look like serial number references on the Conn-Selmer website. Flute also stamped "sterling body and head joint". The flute is in an Armstrong case but I'm wondering if it is possibly a different maker? Just wondering if anyone can shed any light on this.