I did hear back from Karura directly. They asked for the serial # of the case and determined it was built to hold a Martin OM at 4-1/8”, tightly. However, if the foam permanently compressed to fit the SCGC OM, it might not be so perfect(loose) for my other 3 OMs when I travel — unless I put a towel under those guitars. I was trying to “multi-use”. Karura was great to deal wit. They were happy to send materials and directions for me to refit the bottom padding. It requires that I strip out the old mat and glue down a new one. It’s seems to be very uncomplicated. However, I decided to leave the case as it currently exists. It fits perfectly for my 1 Bourgeois Signature OM (4”) and 2 Collings OMs (4-1/8) for travel. I really like the Karura cases. They are lightweight and appear to be very rugged. They are one of the few companies that provide test data for crushing as far as I can see. I plan to order one specifically for my new SCGC OMG and perhaps another for the SCGC OM later. Those Ameritage cases are nice and quite durable, but I’m afraid to say — the heft of those cases are for young backs.
thanks for your reply,
– Paul –