I'm looking out for two of those stabilizer bars that keeps the camera rigid and stops the rail from flexing on an 8x10" Korona. I don't ask for much! Cheers
If you find them, I don't think there is any guarantee that they will fit your camera. I think that like the rear rail, they were matched individually to the camera, so you might as well make your own. Tsuyoshi Ito ("shinnya" on APUG) made a set for his Korona 7x17", if you want some advice. He said they were fairly simple to make.
Eric--On the left and right edges of the base of the camera, you should have four slotted metal disks, two on each side. There are two wooden bars, each about a foot long, with two round head screws each that slide into those slots and fit snugly to the camera base and provide extra support to the front and rear camera rails.