[Brentwood Bob]

As discussed in previous threads, OEM shocks drop oil. Annual spring prep/ maintenance would be a good time to include checking the shocks, although this is not done. Failure, I think, is from neglect. The nitrile seals for the shaft I use should last years, probably well past the 5 years some replacements give. The driver model a's leave oil, and were designed to do that. Salt is not your cars friend. Nor is dust, mud, gravel roads, wind driven sand, small animals, etc.
I believe the "rebuilt"(disassembled, cleaned, new seals, refilled, assembled, tested for function, sealed, and leak tested), Houdaille shock goes on the car, and will give adequate service for a long time. That's its job, and it will do it well.