Reso banjo case with a Goodtime Openback Banjo?

Hi all, im lookin' for a hardcase for my Goodtime Openback, Im thinkin about getting a Resonator Banjo case as they are much more common in Australia (and cheaper). Because they are much roomier, i was thinking i could just pad it out. Is this a bad idea?

Thanks in advance.

and go easy, its my first post.