Another option is this case,, which I believe must be a GAD M-120 case (black, not tweed). It's not fancy, it doesn't have an arched top, but it has a Guild logo and it fits my 1964 F20 just fine.
I rescued an F20 a while back, pretty beat, but the price was right, it's set up nicely & plays great. Everybody needs a spare F20, right ?
Ya'll posting this thread was inspiration to order a case, I pleased to report a 65 Hoboken F20 fits into this case perfectly. Free shippng was nice but case arrived with minor inperfection in the tolex, shipping damage I suspect & insignificant. That bugger Amazon charged me sales tax.