It's probably late 1940's, early 1950's. In the '50s they started using plastic fretboards, so this is an earlier one. Harmony made approximately a gazillion ukes, and no small part of that were branded with Smeck's name.
One in excellent condition might fetch $75-100 on a good day. Yours looks a little tired - kind of looks like there's a crack on the upper bout to the left of the soundhole, the bridge slots are worn, it needs an overall good cleaning. If the back and sides aren't cracked, the seams are good, the neck joint is good and the tuners are original and still good, it's maybe a $40-50 uke.