Is there an authoritative copy of the PDP 11 Field Guide?

[paul popelka]

 blockquote, div.yahoo_quoted { margin-left: 0 !important; border-left:1px #715FFA solid !important;  padding-left:1ex !important; background-color:white !important; }  I've been using Megan Gentry's copy at http://world.std.com/~mbg/ but that seems to have disappeared recently.There seem to be several other copies available with different update dates.
Which copy of this do other people use?Thanks,Paul