Hi there HHB
When I recently replaced the seal in mine, I used the Inox grease in a 30g tube from Jaycar (only $7.95). I repositioned the two o-rings either side of the bump at the top of the steam arm, applied the grease and reassembled.
Wished that I had used more on the thread of the tap when replacing the seal though, as that is now a bit tight. Simple enough job to strip down and redo.