I have often fixed up vintage machines for use, and typically I would put one drop of oil in each "hole", just in case. I usually just add some lube to the gears rather than trying to remove old lube first. I have never used TriFlow, although I have read about it; would have to research that thoroughly before trying.
However, the Pfaff Tiptronic is a really nice machine, so I'd do a little research first. I'm sure there is a vintage Pfaff group on groups.yahoo.com that you can join. Those groups typically have specialists who will give you very accurate advice on how to clean and oil a machine.