Franks gun is certainly an odd duck. If you take into context the statements from Dallas on the Holland grade 2, a first step away from the Climax action and towards the Dominion and the other descriptions of the back action locks from Scott on the site I provided, Franks gun is a possibility. A one of perhaps. Scott did make use of the crossbolt.

This is another Holland a Paradox grade 2, 7 or 8 years after the gun depicted by Dallas.