Since the bomb shell is a metal tube
mod that holds an 18650, you should be able to use a kick and an 18490/18500.
It's tough these days to get recommendations on stacking
batteries in an unprotected
mod. A couple of injury accidents have occurred lately and that has dampened the enthusiasm for achieving HV by stacking batts.
EDIT: The bombshell is anodized on the inside of the tube. You'll need to sand off some of the anodiztion for a contact point. Also, the bombshell is a little bigger diameter than the kick, so a piece of card stock (folded over piece of business card will do) along the opposite side from the kicks contact point should be enough to make it work.