Does MOT allow replacement with other material

Hi to the experts!

Just filled the patrol tank for a long drive when the guy pulling up behind me pointed out that the fuel was pouring out into the road!

Thankfully it wasn't a full tank, just from the overflow pipe which has corroded and split.

My car is pretty old, and pretty rare (I hope it will become a classic, but not holding my breath... as even a classic this rusted would be sent to the big country road in the sky.

Due to this rarity, replacing the fuel filler hose and overflow is nigh impossible. I am at the stage where a custom part would need to be made... until I started looking at alternative materials.

I appreciate many plastics and rubbers are unsuitable for petrol, however I have found several suppliers who sell flexible hosing specifically for transporting petrol from one place to another and hold the diameter I would need. With a jubilee clip on each end, it would perform the task beautifully, seal the fuel storage section again and would outlast the rest of the car.

But my question is

Would this pass or fail an MOT?... Are there specific materials which do and don't pass? Or are the rules pretty much limited to 'if it works on the day, it works'? i.e. a bit of garden hose completing the seal (which I wouldn't do unless guaranteed to work long term by an expert)

Thanks in advance for any and/or all replies