I also noticed the markings - I even designed the tank top with three manholes (see below) - and I still don’t think they simultaneously carried water and fuel - but I don’t have a way of knowing for sure.
I have another update: The real fun begins now - I got my 3D printed parts from the printer today. Here’s how they look like:
The thread-plate looks a little coarse in 3D and in close up, but in person it’s just fine. There’s a whole jungle of supports there - removing them is a bit like solving a puzzle, that can be fun, too! I hope to post some assembly photos soon!
Let’s get back to the real world (from 3D world) - I put the wings on the frame:
I printed them with the supports that help to keep them straight. After the glue (CA) sets, they will be cut off at the red lines.
Then I dry fitted the parts:
Looks like everything fits, yay!
In this case I can start putting everything together:
The photo above also has the 3D printed steering gear and the front exhaust pipe made of 2mm soldering wire and also muffler made of leftover sprue and plastic sheet.
Now I’ll try to fit some more parts - thanks for looking and have a nice day