Loosening a scabbard?

[Dan D'Silva]

I've seen plenty of questions posted on what to do when a scabbard is too loose, but can't seem to find any about the opposite problem. My new wooden scabbard core (for a blunt combat akinakes) is threatening to be a total bust. I spent hours tuning the fit before gluing the shells together, but I figure glue must've seeped in around the edges, and now it's too narrow.

Anyone have any suggestions? I figure as a last resort one could soak it until the glue dissolves, but of course that might warp the wood.