I picked up a G&B pump thinking that it was either a model 904 or 906. On inspection of the ID tag, the model is 1004-36L. I don't find a reference to a 1004 in Jack's book, unless I am overlooking it. The only difference I see between the 904 and 906 models and the 1004 is that the 1004 doesn't have an ad glass window below the face plate. Can someone provide more information on the G&B 1004 or direct me to the page on which it appears in Jack's book? Thanks.
A picture of one door panel from the 1004 is included below.
