Of all the birds I’ve owned, the only one that won’t fit into one of my Epi cases is the 1964 Gibson. It’s a combination of the bottom strap button having moved and the shape of the lower bout. You can see this in the photo. Even with the strap off, it doesn’t want to go. It fits snugly in my other Epi case, and just fine in the Roadrunner. Both Epi cases are the modern trapezoidal shape.
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Actually, I’m sure the PRO 5 would not have fit, if only because of the aircraft carrier neck. But it’s long gone (because of that neck).