Reasearch leads me to believe this is a 1939 American Clipper "A". Yellow gold on original bracelet and shows no signs of wear. Case and band are as reflective as a mirror with no scratches, brassing or scuffs. Crystal is perfect. Dial is a bit chalky in appearance, likely from a poorly orchestrated cleaning.
Movement bears both a shield for 1939 and a crescent moon for 1938.
Online auction purchase - it was initially listed as a women's watch (nobody was watching) - $25 including shipping. Inside of back has a jeweler's mark (sharpie pen) indicating the last service was in 2005. Keeps perfect time.
Here is my thinking on AC "A".
It is advertised as "Bracelet" or "Pigskin" band. Pigskin is seen identified as AC "B"
Black Face on bracelet is an AC "C"
Yellow gold with white face on bracelet with engraved case and bracelet is an AC "F".
This ad from 1936 lists pigskin band on yellow gold or mounted on bracelet in either yellow or white. I'm not prepaired to go here yet, but suspect bracelet version in white gold was either the missing "D" or "E" variant and perhaps the other is black face on pigskin or in white gold.
I would hesitate to assign either "A" or "B" to an American Clipper without a verified original band, but subject watch has it. American Clipper "A" for me.
In reply to I agree it's an American by Geoff Baker
I went by process of elimination for the variant letter. Earliest ad shows three variants based on band and gold color. The pigskin in yellow gold is later identified as "B". No further mention in ads of bracelet model in white gold. "C" is black face on bracelet in yellow gold; leaving "A" as bracelet/yellow gold/white face.
In reply to I went by process of by neetstuf-4-u
In reply to Just reading through this by Kathy L.