After doing a bit of research, it looks like the "Rev 1" 16K RAM board that Bill Degnan
has is most likely the prototype/development version of the board and "Rev 0" is the
first production release. The revision on the board actually shows "Rev 1-0x" or 
"Rev I-0x". The "Revision 30APR76" documents show the Rev 1-0x board be modified to
become the Rev 0 board. The Rev 0 board, in turn, is shown in all the advertising
literature and manuals. The April 76 date pre-dates the Rev 0 board. The "Rev 1-0x"
board has no silkscreen and no solder-mask which is also consistent with being a
prototype version.