My first urge here is to thank Kieth Williams and Erie Patsellis for their patience and advice to those of us less experienced in their domains with LF and MF cameras. I am merely a novice with these issues, but have already noted a striking familiarity in these informal discussion groups (forums), where this and other threads repeatedly wander through similar issues, sometimes with contradictory advice. For someone with my background (formal science) these discussions are of sufficient sophistication to benefit from the kinds of formalism that earlier evolved within (what are now) specific "scientific disciplines."
Have your senior APUG contributors considered forming something like an online "APUG Journal" with editors, peer reviewers and an online "library" of technical literature on subjects that keep cropping up in multiple discussions?
Erie's technical adaptations (noted above) are essentially "inventions" that should be documented with diagrams and photos (for newbies, as begun here), and posted as downloadable pdf files that can be referenced by detailed citations (E. Patellis, APUG J., 2:1-10, 2009; or whatever). This would eliminate the need to rummage through cyberspace, only to find that his website currently cannot download to one's browser (as had happened for me here).
With people coming to "serious" photography from so many different backgrounds, many just now discovering the advantages of "film," and particularly its larger formats, such organization would greatly facilitate their transition to newer advanced subjects that have not already been explained repeatedly in earlier discussions.
To return to the current thread, detailed advice about creating 6x9 (or even 6x8) film backs for the RB and related MF cameras would be a big help, since these (rare or nonexisting items) are for many the only realistic LF options under current conditions. Most readers will, however, be even less familiar with the (suggested) "Graflex RH holder" and where to acquire such exotica.
Also, most recent recruits into MF will have come from backgrounds with smaller format cameras, and would thus welcome explanations of how their existing gear (macro lenses, bellows, extension tubes etc) might also function (occasionally) with the amazing MF or LF cameras they have just "discovered." This leads to the mostly unfamiliar zone of "lens mount adapters" on MF cameras for assorted 35mm gear. Someone should commissison/write/edit a review article...?