I know these printers well, if the heads actually still had drips hanging on them the heads are probably in better shape than you think. The fact that the rest of the carriage is so clean indicates that whomever took care of this printer in the past was very good and detailed in the daily cleaning.
This is what I would do - get some Gumout carb and choke cleaner ( in the spray can ) and spray the heads, let it soak about a minute, then wipe off the residue in short strokes, and keep turning to a clean section of your lint free wipe. Then fill the heads with printhead flush through the vacuum tube connectors on head #1 of each color. ( no more than 60ml for each color set ) then reconnect the vacuum lines. Power the unit up with the heads filled with flush. Go into the printhead procedures, and fill all the heads with air. ( empty of the flush )
Next go into the service menu and enable the hidden items ( device test>pod test> UUUU, UDUD, UUDD, UUUD ) that will open the prep for shipping option, this will empty the heads, instruct you to fill them with flush, and it will agitate the heads for a while and dump the flush out. ) I think the procedure goes through twice, but I may not be remembering it perfectly. After that is done, fill the heads with ink, and I would expect you will be in pretty good shape, mostly because the ink on the heads was still wet, and secondly because of the great care that was taken with the regular cleaning of the heads by the last owner.
Good luck.