If I were a collector of bicycle badges (a subset of this hobby) and I lived in a small apartment as Untitled has mentioned as to how he resides, my challenge would be how to enjoy the hobby; procuring, displaying, storing, and maintaining my treasures without being overwhelmed with the abundance of complete bicycle frames? So hell yeah, I would pay big dollars for an H-D badge if it were to advance my compact collection.
Personally, I don't see the aesthetic appeal of the Harley bike itself...to me it's just a standard Teen frame very common for that era. And since Harley Davison never produced the bike, I don't understand all of the hoopla? Wasn't it the Davis Sewing Machine company that manufactured the bike and badged them for the H-D dealer network?
So my answer to your question is, no I wouldn't attempt to restore a Davis bicycle if it wasn't originally H-D badged