Hi Mats,
I will try to answer but it is not easy !!
1/ I understand : between the body and the fender there is a joint. We made it with a thin canvas folded over a rope
2/ I guess they are the same but not sure, we used similar ones
3/ you can see pictures on a post of 2011, Mai. It looks like a wool bed cover. For the floors, we used Fermacell
4/ I can't find picture of it but it is similar to the ones of the main lights but smaller
as the truck is rather far from home, I won't be able to make a picture right now...
sorry, I am not able to help you much
Regards,
Pierre