Loved the series. I have been using the 350/400 since the 90s with thousands of dives on them. All of my student rigs are Mk20or25/D400s.
I just added this very nice original Pilot to my collection today.
Gotta tune it and would love to talk to Rob about that. I probably have parts in a bin somewhere.

Scored a Dragar Nemo. Is there a number for the seating O ring?