@neauoire Ouch. I had the same plastic covering on the standing rigging and the lifelines on Astragale. I removed them too when a more experienced neighbour told me about the risk of hidden corrosion. Thankfully it was early enough - and the previous owner had put a lot of grease inside the sheathing so it was dirty and sticky at removal but it probably helped protecting the lines!
@mapper nice, that's lucky! Do you keep a page on your sailboat projects somewhere btw?