I acquired this metal "thingy" in a box of other antiques. I don't know what it is. Do you?

It has a long, thin handle like a spoon, but the working end is round and flat.

I'm thinking it has something to do with soldering or bronzing. but not really sure. Need to know what to call it, cuz I'm gonna list it on eBay.

The piece is 8" long.