People might be interested in this mod to a friend's 4x5 Super D that lets lensboards be attached to the front of the camera, allowing mounting of lenses that are too big to fit on a 3.75" board; lenses that have a barrel projecting back into the camera that would otherwise foul the mirror; or getting a few extra inches of effective bellows extension.

He's added an early model Home Portrait Graflex-style front standard to his Series D. It's one way to deal with limited bellows draw. Others are using lenses with long barrels, or getting a double-extension RB Auto Graflex. Both are more expensive. This is a cheap-but-effective solution.
Issues might be light leaks in front standard, and seating lens-boards light-tight. Modifying that camera isn't a big deal, IMHO. The series D Graflex isn't a rare model. Not having an 'automatic light shield' is debatable-I find it in my way at times on my RB Series D, but it works when shooting outdoors, and I don't have the heart to cut it off of a near-mint camera.