I thought I'd used that focal length before, and had. The combined cells make about a 7" lens. I used one on an 8x10 camera a couple times when I didn't have anything else wide enough. I came surprisingly close to covering 8x10, just nicking the corners. The one one I had looks to be a similar vintage to the one in the auction (mine was barrel mount).
Originally Posted by Ian Grant
The B&L catalog I have (probably the same as in Ian's link) indicates that the relatively common (for not very common lenses) 11 7/8" (18 7/8" and 23 1/4" cells) should cover 11x14 when stopped down. I have that lens, but nothing larger than 8x10 - except Cirkut Cameras.
I think for any useful movements you are going to need the far less common #20 combination with individual cells of 27 1/8" and 23 1/4" and a combined focal length of 14 5/16". I believe that is the combination Walker Evans used on 8x10 for his RA/FSA work, though his was the Zeiss version marked in cm or mm. It is mentioned in the "Walker Evans at Work" book, but I believe they have the combined length wrong (my book has failed to come back from loan, so I can't check).
B&L made longer cells up to 39 1/4". Ken Hough found some of the longer versions in the Chicago area I believe. Any of the Protars with cells longer than 23 1/4" are hard to find.