The printer looks very much like the HP Designjet T7100 you linked to, but take a look at the diamond shaped blue logo; the logo doesn't look like HP. Maybe the printer/plotter is a rebadged HP?
I ignored the badge, as you say it could just be a rebadge, Dell do this (or did) with their laser printers, IE stick their own badge on it when its actually a Samsung, Brother or similar.
The easiest way would probably be too look behind or under the thing where there is bound to be a label with the model etc details on it. I assumed it was just a guessing game for us all though