Well, having exchanged the Pacemaker Graflok back replacement I got from 20th Century Camera for one newly made to convert an Anniversary (and hoping it'll hold in place; the screw holes look oversize for the heads of the original screws) (EDIT: Yep, it went on, with near-zero tolerance in the screw holes, but once they were all lined up, they went in), I went to install the ground glass in the focusing panel I purchased -- and found it won't fit. Not just an issue related to the Ektalite field lens; the ground glass I have in hand is too big for the machined pocket in the panel -- and the panel doesn't quite match the description I'm finding on the Graflex.org FAQ pages, either (hood is a friction fit rather than held with clips, ground glass is held by a frame a half inch deep instead of the two swallowtail clips in the above photos).
Which is probably because it's a Graflok focusing panel & hood for a Polaroid MP4, says the clearly visible nameplate inside the hood.
I've tested it; it latches and unlatches correctly on the Graflok conversion back, and the depth from the contact surface to the ground glass step is correct at 5mm, so it will
work (albeit with undersize viewing area) -- but I'll need a smaller ground glass. The actual dimension of the ground glass pocket is about 79x105 mm -- was the MP4 a 3x4? I could still return the focusing panel (clearly described as for a Pacemaker in the
eBay listing), but I haven't seen a lot of Graflok focusing panels going by, and the ones I've seen were either complete back mounts for some other brand (Sinar, etc.) or a different size (there's a 3x4 on there now).
I'm confident I can get a ground glass to fit this MP4 focusing panel; I don't know that I'll use the ground glass all that much anyway (the RF works and is calibrated for the lens I usually use, and I expect to use this camera mostly with Grafmatics and the upcoming Lomograflok instant back and RF). I suppose a "hedge my bets" option here is to get a ground glass that fits the MP4 back and keep looking for a correct Graflex 4x5 Graflok focusing panel, and plan to sell the MP4 panel on once I find a correct one.
Opinions?