I use Elmers on painted tubes. After it dries I brush on a coat of watered down Elmers and let it dry. Modge Podge would probably be better than diluted Elmers, it has more body and will build thicker. I moisten the leaves with water to make them wrap better, so you will need a water based adhesive, collagen based glue might be a very good choice. . . if you happen to have a dead horse lying around.
I cast them in poly resin because I like more shine than I get from urethane. Slow drying poly resin tends to saturate the tobacco leaves and turn them grey, so the top coat is needed. Aluminite may not do that as much and therefore you may not need the top coat.