Anyone heard of a Selmer S-552 Flute?

[wind player]

I recently acquired a collection of instruments from a retired doubler and the flute in his collection is labeled Selmer / Elkhart, IND. / S-552.
U.S., slashes indicating different lines.

I'm looking for information on this flute. It's a closed hole, C foot flute that has a very nice sound and response from what I can tell (as a saxophonist). No serial number that I can find, unless the S-552 is the serial number. I've searched and can't find any info about this flute and possible value. Any help would be greatly appreciated!