PeWe, I also thought using both seals would be a good idea for extreme duty. I pulled 6 pair of forks of the shelf and didn't find one good matching pair of tubes. Some fool ruined the F0 tubes by sawing into each one and all of the 341 forks had wear through the chrome and rust damage near the fork seal area.
That makes me wonder what wore through the chrome in the seal area and how much that wear transfers to the lower fork. I haven't seen that wear on early type forks.