See http://www.cameraeccentric.com/html/info/ilex_2.html p. 6, and the table doesn't include a 12 3/4 incher. Also see http://www.cameraeccentric.com/html/info/ilex_2.html , which explains the name and also doesn't include a 12 3/4 incher.

Re the second lens, wander over to http://www.cameraeccentric.com and look for yourself.

I wouldn't buy either so any advice I give should be very suspect, but if the f/6.3er is a tessar type it seems a more attactive proposition as a normal lens for 8x10 than the medium w/a.