Option of soldering or gluing the frame from Ø1 mm wires comes to mind. In that case skip the following up to floor and wheels. Paper puritans read on :-).
Print whole page on a cardstock about 0.4 to 0.5 mm thick, or laminate it to that thickness. It is necessary to achieve this thickness quite precisely to make all the "rods" square in the cross-section. Laminate the area in red rectangle (parts 3, 8 and 9) by one more layer of the same cardstock.
Set print scale to 1:1 by DPI (or anything that suits you), turn "preserve aspect ratio" on and "fit/stretch to page" off.
You will also need a piece of straight wire for wheel axles, a bit longer than the carriage is wide (at least 40 mm - it will be needed for aligning the parts properly; at the end you will need just two short pieces of it; a christmas sparkler holder worked well for me), piece of office paper to roll wheel hubs from, a spool of thin sewing thread for the spokes and a piece of corrugated cardboard, three needles and one nail of about 1.5 to 2 mm diameter for the rigging jig. And, of course, some paints, because the "kit" is all white.
Cut out parts 1 and 2 and glue them together back to back (separate cutting - at least of the inner perimeter - is necessary due to the little holed rectangle which is only on one side). Punch the axle holes before cutting. Glue the transversal rods 3 - first the top two to one of those ovals (keep all angles right using some cubical object until the glue is dry), then attach the second oval and finally add two bottom rods.
Glue parts 4 and 5 back to back (they can be cut after gluing to save some work, but you will have to cut more carefully then) and edge-glue axle holders 6 to parts 4. Prepare two U-rods made of parts 7.
Insert the axle wire through the holes on the main part of the frame. Slide subassemblies 4+5+6 on the protruding ends of the wire and glue them to ovals 2. Add parts 7 to the top. When the glue is dry, it is safe to pull the wire out - all holes are now perfectly aligned in one line.
Glue short rods 8 in the corners between ovals 1 and upper rear transversal rod 3. Bend handlebar 9, glue its ends to the two remaining free circles on parts 1 and then glue it where it touches parts 8.
Paint the frame afterwards.
Assemble the floor from the deck 10 and connecting planks 11. If you want it to look better, cut the desk to separate planks before gluing parts 11 on it, but be careful - it expands sidewise and you will have to narrow some of the planks down to get back to the original width.
Paint the floor and insert it into the frame. It's sorta puzzle - you have to turn it 90°, insert through one of the side ovals and then turn it back (the more indented corners belong to the back). In reality, the floor is usually laid freely and held down by gravity, but here I recommend to glue it, because it tends to travel and fall off.
Glue disks 12 and 13 back to back. Glue template A to a piece of thick corrugated cardboard or something similar, so needles and nails would hold well in it. Make the spokes from a sewing thread, detailed tutorial is over here (warning, online only). Part 14 shows approximate dimensions of wheel hubs, roll them from stripes of office paper (both diameter and thickness may need little changes to fit your needs). Snap two pieces of wire according to template 15 and install finished wheels into the frame. If you worked precisely enough, the cart should be able to ride.
I hope your build went well and you now have an interesting bit of accesory for your collection of 1/32 vehicles and construction machines. I wish you sharp eye and steady hand and see you around another models!
B@F
This and other kits can be freely downloaded from PaperGallery.ic.cz.