Is it BO and LO or is it B0 and L0….that is the question??

People are starting to bring up good points but it looks like people are showing reprinted documents. Does anybody have any paperwork from back in the day clearly stating the letter O or the number 0?
Well quite frankly many of us didn't have the good fortune of knowing anyone originally associated with these cars, hence copied documents. Anything on the internet or anywhere else is going to be "copied". A disadvantage for sure. Some on here have an original document and even maybe an original car so if they can't produce anything written then what?