FYI, Right or wrong, there are several (many) amateur built airplanes with
corp's  or multiple individual names listed as the Mfgr.  

Here's a few quick examples which I found on the FAA's records.

Google the N-numbers and look on the FAA registration site for yourself.

N Number, Mfg, Mfg Date
------------------------
N1014Z, 101 Flying Assoc, 1970 (Thorp T-18)
N107FP, 107.5 Flying Corp, 1998 (DR 107)
N293RG, 293RG INC, 2006  (Lancair IV)
N300KM, 300 Knotts INC, 2000 (Lancair IV)
N900RB, 900RB LLC, 2006 (Epic LT - seems this one would have been under a
lot of scrutiny)
N29GJ, ADKINS GEORGE & ADKINS ANDREW, 2005 (an RV-9)
N495SL, ALAIR S C/ALAIR L P, 2004 (Legacy)
N242S, ALLISON D/ALLISON M, 2006, (Lancair ES)
N666AR, ALPHA ROMEO HOLDINGS INC, 2004 (F1 Rocket)
N5969X, AMERICAN AIR RACING INC, 2005, (Lancair IVP)
N915TR, AMERICAN LONGEVITY CORP, 2005 (Searey)
N550MH, BARTLETT D/JACKSON J, 2005 (Lancair ES)
N7SY, BEAN R E/R B WELD INC, 2003 (Glasair III)

Rick