Hello & welcome to the site...
I’ve used the small/8-oz. size Coke bottles with no problems in Vendo V81’s with the reproduced shelves without the sliders, you just have to adjust the shelf forward enough so that the crown of the bottle clears the edge of the gate/portal. The only time I’ve run into vending problems on customers V 81’s & 56’s is when the shelf isn’t seating on the edge of it’s matching port. Or the machine isn’t level & plumb. It’s a gravity fed machine so there’s little to go wrong, unless a shelf is warped or something twisted with the ports floor itself.
BTW where did you get the Oso grape?
Thanks for the welcome!—so happy to have access to all this info and expertise!
I have the shelves adjusted forward and seated properly. Will check the level of the machine. Even though they are small bottles, I notice the bottom of the bottle kind of catches as I pull it out—even though bigger ones do not. Any idea what this means?
I live in the Minneapolis area and buy the Oso grape (and other craft sodas) at Lunds/Byerlys grocery stores in the area.