There's no way that a Graflex-made roll holder will fit in the slot that accepts the "blue" film. None. Give up on the things, they won't do for you. And they all, except the much deeper RH-70, have the same depth, there's no rare variant that will save you.

FWIW, I just measured an Adapt-A-Roll 620. The insertion end is 17.3 mm front-to-back. As I've told you, an AAR 620 won't attach to a Graflex (that's Graflex as in Graflex SLR and yes I have one) back. It can, however, be used with a standard spring ("Graphic") back as on the newer Curtis you showed. You may be able to attach spring backs to your Curtis. But and however I have no idea whether an AAR 620 will fit in your camera's "blue" slot or what would hold it snugly against the gate.

Why don't you just get three 2x3 Grafmatics for Graflex backs and do as Henri Gaud does? I think he's farther along than you.

Alternatively, and this will be a real pain, you can put a single sheet of film in a pack adapter. To take more than one shot in a session you'll have to have a pile of pack adapters or reload using, e.g., a changing bag.