Many thanks for your nice comments, gentlemen, they are highly appreciated!
I would like to create a vignette corresponding with the photo, but I am not sure if this will be feasible - the tracks are partly missing on the lower side, where I had to cut the parts off. But perhaps I will be able to make it invisible using mud.
Yesterday I started gluing the PE parts in place, I was quite scared of it but eventually it went rather smoothly:






Cheers.
Ondra