Thank you friends !
A bit of progress, the upper hull and the mud guards are on their place but it wasn't simple, there was a section that I had to fill with plastic sheet between the hull and the mud guard, the open areas would make the gaps visible. Also the front section on the mud guard is completely missing in the kit so I had to scratch it with brass plate, but actually this is fine for me, on later stages I can simulate some damage on them....