Originally posted by pathdoc I think it's doable. I think a couple of engineers with Ricoh laboratory resources could jury-rig it. I'm not sure you could fit it inside an ME or MX; you would probably have to settle for a Spotmatic or K-series body in the first instance. But I think it could be done. The hassle would be getting Ricoh to actually do it.
Or else. . . You could just go ahead and buy a Fuji X-T1 already. You can switch off the back LCD, switch to manual focus, and take all the dials out of the A-for-Auto position, and you are there. Oh, and pick up a K-to-X lens adapter too, why not? (Although the native Fujinon prime lenses are superb!)
Oh yeah, I must admit it doesn't have a big, beautiful OVF with a split-prism focusing screen. Instead it has a big, beautiful EVF with your choice of magnification, focus peaking, split image, and simulated split-prism focusing aids.
There's a company already going out of their way to cater to your retro impulses. Don't shun them just because they aren't Pentax.
Pentax have chosen their own path and their own style, and it's all about modernity. The K-S2, K-1 and K-70 are the clearest expressions yet of Pentax's vision, and that vision is nothing like what you're asking for. It's just not in them.