Given my storage needs required my D cell batteries to be stored in a single row, I adapted the model files from my two-row model to use a single row with a retaining divot on the opposing first and last gaps.

I have noticed the circular cutouts in the case will rub up against the sides of the cylinder - But it works well for my use case and if you have something roughly cylindrical that's preferable to stow in a single row it may work for yours!