Haha, I was all of 11 or 12.
The racing set had been a Christmas present, and I augmented it with months' worth of allowance, a few pieces at a time, then some nicer cars, slicks and mags!
My dad and I built a shallow box, probably 6-8 inches deep, with a plywood base.
We may even have seen a cartoon mock up in Popular Science or Mechanics or Science Digest magazines; we added hinges at the back so it could be lifted and stored against a wall, out of the way! The heaviest part was the plywood, likely 1/2 or 5/8 inch.
I had set up the track, with some tight loops, slopes, and straight aways, some stretches elevated, traced its outline, then removed it to be re-attached later and screwed down. The trellises and supports for the elevated portions were left to work around.
I remember mixing the flour and water and pulling endless strips of newspaper through the mixture, laid over an armature of cut shoe boxes, balloons and crumpled newspaper held down with masking tape. I must have tacked it in several places to keep it from lifting when in the upright position.
I also remember how black my hands got from the ink, and the smelly mold that formed on the rim of the bowl as I wasn't that careful to clean it after every session! So it took a few weeks or more, a couple of layers at a time, always waiting for it to dry before the next layers.
Haha, now I also remember using my mom's hair dryer, in those days a big unit with a hose that fed into a 'tent' ladies would put on their heads!
Not being plaster, it weighed relatively little.
Then I used a combination of 'grass', 'sand' and 'gravel' from the hobby shop along with pebbles, stones, twigs, dried moss and lichen from the field behind my house, all glued down with white glue and painted cliff sides. At some point I must have put the track back down, and was as careful as a twelve year-old can be reaching across to install landscape.
I had also found scale figures and animals, which I painted and glued down. Wish we had thought to take a picture of it!
Then hours of fun with my younger brother and friends, racing our cars round and round, with criss-cross lanes, cobble track and rubbery gard rails that had been so hard to put on. We were delighted with some spectacular crashes to boot!
Cheers!
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