I'm a little confused with the body depth numbers being thrown around. While I don't have my B-500CE sitting in my lap, since it built on a Prestige guitar superstructure which is essentially a flat top version of an X-175/500, I believe it's only around 4-1/2' deep! It shouldn't require a very deep case.
Grot I suspect you've just forgotten that it's actually a 6.5" deep body (otherwise Kat wouldn't be having this problem).
Even though the
outline comes from the Prestige, I suspect the bass version has a deeper body along with bracing differences due to different soundhole and bridge placement, and bass string tension.
I suspect this is why cases for some of 'em are pretty hard to find, and the headstock size issue adds another complication.
The case I bought has a depth of 6.25”. I can fit it in by jamming it, but the case needs to be wider and deeper. Due to the lack of a curve, I can’t close the case and the neck is about a half inch off of the rest. The headstock appears to be too wide for the case as well. I don’t have measuring tape to measure the bass with, or else I could get the exact dimensions. I think the depth of the case needs to be 7”.
With Guild cases at least, as I explained before, they don't actually have a "curved" back, they're just deep enough to accommodate an arched back, which requires a uniquely-sized case for some basses.
That neck rest issue and headstock size are obviously coming into play as well.
Since HA's was gone, I'd pester GC again.
I think if it's buried in their storage it'd still be pretty big and hard to miss, if somebody knew what they were looking for.
Offering a case that didn't actually fit was pretty lame and almost worse than nothing, but I'll try to give 'em benefit of doubt as a misguided attempt to try to do something nice for you.
Or, hate to suggest it, but send it back as you were thinking, before you bond with it.
For me with my Guilds at least, the case is part of the instrument.