Why would you want to do the job twice though?
I agree on that principle - although it looks to be a quick and easy job on it.
But you are the one who is always suggesting not using genuine parts (which are generally of a known good quality)
There
are parts that I'll use genuine for preference. But basic parts like gaskets, plugs, oil, filters, belts, brakes, radiators, exhausts, shocks, arms etc are chosen by how well they fit a mental cost/convenience/quality/hassle-to-fit Venn diagram. Remember, I'm not hard on things; 25k miles on budget tyres, 50k on the brakes, 25mpg average fuel economy etc with an Omega, and my other cars have lasted similarly. So for
me, genuine is rarely worth any extra.
There are things I won't buy based on experience, like Denso plugs or Intermotor ignition parts. I prefer current stock to NOS for older cars too, especially for anything with rubber components. I've had too many fail in too short a time.
Leak off pipes are a common part that I would buy over the counter from a trade/industrial supplier. I can see several of them on the industrial estate that is a mile from my house - although I do have to go further than that as it's the other side of the river - or from the diesel fuel pump reconditioner that's about 1/2mile away.