Finally I had time to try to make a key for this nice old padlock.
I started by looking for something that would fit the keyway, and found this small L shaped metal bracket.
I used just two flat files since don't have a mill or a drill press.
First of all I had to make the blank, by thinning out the sides and cutting a groove in the center of my bracket. Easy



Then I smoked the blank with a bic lighter to see where the warding was. I found the grooves position (circled in red) and filed a few strokes at a time, then cleaned the blank, smoked again, inserted, turned to get the marks and filed again. After some time the blank was finished so the warding stopped marking and it turned a lot.
This is when I realized Richard was right, a blank can't open the lock since the tallest levers prevent it to turn enough to lift the short ones.


The levers left very distinct marks on the smoked blank, you can see three of them in the following picture.

To find out where to file I insert the blank and turn it, while looking at the levers from the shackle hole.
I started filing the two bottom positions, since these two levers were the first to move and arrived till the end of the lock.
Then I filed the others too, testing the blank every few strokes. The goal was to make the lever move all together.
When I though the key was ready I tried to close the shackle and tested it. It was a bit rough but opened the padlock.



Then I smoked the key and fine tuned its cuts, till it turned completely and opened the padlock both clockwise and counterclockwise. The key works now very smoothly, and is reversible.
I'm planning to cut the bracket and give this key a nicer bow shape. Then I may buff it with a polishing compound... I'll keep you updated.

I had a lot of fun with this project. Creating a key from a piece of metal is something really rewarding. Thanks Lauren for inspiring me with your beautiful work. I brought back to life this antique padlock, I'm very happy!
Cheers
