I'm sure someone will have a better answer eventually but I would do one of two things. First I would call Gibson, or a large Gibson dealer, and tell them your model and they will have suggestions for alternate cases. Secondly, I would take the guitar to a large-box store (if one is close enough) and personally do a fit with the guitar. If those two don't work for you I would then give the measurements of the guitar to a guitar case manufacturer (several on the web) and they will tell you which case is most appropriate for that model/measurements. Happy hunting.
Martin D-41, Gibson J45 Custom Shop Southern Jumbo, Gretsch G5120, Martin SWOMGT '07, '08 Larrivee OM-03RW 12/12, Epiphone AJ200SR/VS 2006, Voyage-air VAOM-04 ....et al