Mr. Google and I have checked the archives here and elsewhere regarding the wide-angle lens for the Koni-Omega RF system. To review quickly, there were two such lenses, a 60mm f/5.6 and a (later) 58mm f/5.6. The issue is whether these were in fact the same lens.
It's a popular belief that they were. Here's a sample RFF thread where the consensus seemed to arrive at that position. (And there are some interesting hypotheses as to why the designation was changed from 60mm to 58mm.)
Further, the article at Camerapedia says this: "There is a 58mm f/5.6 wide-angle lens. The actual focal length is 60mm but for various reasons is marked 58mm."
Now thanks to Mr. Butkus, there are complete user manuals available for most of the K-O cameras. Here's the manual for the early K-O Rapid cameras:
And here's the manual for the later K-O M and Rapid M cameras:
And finally, here's the manual for the Rapid 100/200 series:
(Thanks, Mr. Butkus!)
On p.17 of the K-O Rapid manual (first Butkus link), you'll find lens diagrams and descriptions for the available lenses. In the M/Rapid M and 100/200 manuals (2nd and 3rd Butkus links), the same information appears on p. 21 of the file.
OK, here's the deal: The Rapid manual shows the lens diagram for the 60mm f/5.6: The design is six elements in four groups (6/4)
. The M/Rapid M and 100/200 manuals show the lens diagram for the 58mm f/5.6. The design is eight elements in four groups (8/4).
Both designs are of a symmetric type, but 8/4 is different enough from 6/4 to support the conclusion that the design was re-computed when the lens description changed from 60mm to 58mm. And in that case, the Camerapedia claim about the 58mm lens,
"... The actual focal length is 60mm but for various reasons is marked 58mm."
would seem to be wrong.