swivel oil seal replacement - do i need the gasket as well?

hi
i tried to get swivel oil seals last weekend from an indy local to me, gave them part numbers for seal and gasket that i got from thread search:
https://www.landyzone.co.uk/land-rover/swivel-seals.220515/
thanks james!
anyway, they were perplexed by my request for gaskets - saying they couldn't understand the need for them and wouldn't think to fit them - so they didn't have any or even find the part number at first on their system?
so i ended up not doing it. i want to do it this weekend as i have ep90 all over the place after filling them up - it's basically just all leaked out again in a week!
so, do i need these gaskets or not?
i can get them from land rover parts who quoted me £2.50+vat each, jeez. or 50pence from paddocks
strange world.

you can use rtv silicone sealant ,but i tend to fit gaskets if i plan the job,
ftc3646 ball to axle gasket,if you plan on undoing top pin bolts to remove brake hose bracket from swivel ,place jack under swivel until bolts are replaced

ok thanks!