1930s - I acquired an old 24"x24" embossed steel US-41 highway sign in the hope of converting it into a US-27 sign. It weighs 9 pounds. The "41" had been applied, not embossed. So I figured it stood a good chance of becoming a US-27 sign...

The first step was to sand-blast all the paint and rust...

My friend Jerry sand-blasted the front. It was slow, tedious work. Not difficult... just slow.

It took Jerry an hour to sand-blast just the front. So we decided a better course of action would be to simply take the sign to a local plating shop that could dip it into a tank of chemicals. The chemicals eat off all the paint and rust, returning the sign to bare metal...

Back from the plating shop, the sign looked like new. It reminded me of a 1982 DeLorean, minus the cocaine.

Then I sprayed a coat of gray primer to the front and back. It was now ready for some serious paint...

Jerry's friend Ted painted the front white, then dried it at 140°. A beautiful finish, almost like porcelain.

I then painted the embossed surfaces with black enamel.

The last step was for Bob at the Sign Shop to apply the numbers. He consulted an old specifications book for correct font, size and location of the numbers. Then he used a computerized cutter to make an adhesive acetate...

He aligned the numbers before burnishing them onto the sign...

Then he baked the sign in a 300° oven under a vacuum seal.

The finished product. From this to this. Not bad, eh?!

In case you're curious, this is the kind of die used to emboss steel US-route signs (my thanks to Jake at AARoads.com for the photo).