Old Time (before LEGOs) American Plastic Bricks

My house when my brother and I were young kids was awash in building toys. Coming from a family of engineers and builders, I expected nothing less. I promised myself that when I started fooling around with these 3D printers I would recreate one of my most favorite toys, the American Plastic Bricks. Any internet search will yield a whole lot of information on these toys. Since I fell ill a few months ago, and with a lot of free time on my hands I took out my 6-inch caliper and went to work