I think if I were to date a bike, I'd date something a bit younger - with more curves.
Seriously - the tank doesn't look tp be reproduction; if anything, I'd call the galvanized coating out as proof that it's period - correct. fuel tanks from the 'teens and '20's were often galvanized to prevent internal rusting; my Model T tank in the hotrod is just that.
If anything - the tank may be a period aftermarket piece - an accessory a kid would add to make his bike look more like a motorcycle. Doesn't look like an H-D badge, either - but something made to look like an H-D.
If the wheels belong on the bike, I'd guess teens; otherwise early 20's. Was looking thru some pix of my last trip to the Bike Museum in New Bremen OH, and they had a H-D motobike on display from the mid teens (1914? 1917?) with wood wheels, but the later moto bikes from the 20's had steelies.
It's really nice, BTW.