Ok, so I got a spare tank off Damon and thought since it was off the car I might as well make sure it's future-proof enough to outlast the rest of the car. The outside is all POR15 painted, which I might just go over, but I thought I might seal the inside with that POR15 tank sealant stuff too. Anyone had any experience of using this? I'm guessing Ian has, lol.
Plus, the filler hose could maybe do with replacing. Certainly the little overflow/breather pipe has cracked, though this is easy to replace as it's just flexi 15mm fuel hose. The filler neck hose is the problem; it's 48mm diameter and proper fuel necks with bends only seem to come in 45, 51 or 57mm diameter

You can get Samco silicone "fuel" hose in 48mm but it states it's only for short-term exposure to fuel, not for permanent immersion or transfer of it. The bend in the original pipe is gentle enough that you could probably get away with a straight run of silicone pipe without it kinking, but I don't want to swap in something that's going to degrade quickly. The original isn't in too bad a nick, but is it worth taking a chance on putting something back that's probably already 30-odd years old?
Finally, gaskets... is there any way of discovering parts numbers for the cork gasket on the lift/return pipe plate and the rubber gasket on the fuel sender? Is there like a Mazda parts list online anywhere?
Thanks as always in advance