Seems like you are developing an understanding of how it is designed. I have never removed the loop from the fixed end and so I was only guessing how it is made. To see how my guess of 3 loop single line is made have a look at “ Cabrinha 2020 bar broken main line “, just below main notice board. Personally I have not taken the loop out of the fixed end and so you will now know more than me.
Good luck with whatever you decide to do! (Have a look at the Marlow website if you want to know about splicing.)
Uk eBay has 2m lengths of12x8 pu tube, fairly cheap!