I am considering purchase of a Horseman VH-R even though it is only 6x9 format. I am also considering purchase of a Horseman Increasing back (6x9 to 4x5 inch) that will allow me to shoot 4x5 as well. Do the Horseman Increasing backs accept Graflok type roll film backs or only non-Graflok backs? I realize there are obvious other options for 4x5 and can buy Graflex made press cameras with Graflok as well as Linhof etc. But the Horseman is a lot lighter although with the addition of the Increasing back the weight difference may be insignificant. increasing back? Does anyone have any knowledge about the Graflok compatibility issue with the Horseman 6x9 to 4x5 increasing back?