I've been making my own for years. I make them a little bigger tha hhwat you have and out of 1/2" x 1/8" steel flat bar. (They have to be strong. The day will come when all your weight is on it if you ride fix gears in traffic.) Because these large weights rotate teh pedal down,making pick of that tab hard, I weight the front of the pedal with heavy washers.

The big tabs are a blessing on the fix gear in hills. Yes I lug another excess ounce of so of weight. But just one stop midway up the hill and missed pickup will cost me the rest of that day with the next very hard pedal stroke with no speed at all. And reliable, quick starts in traffic makes for much more fun riding.

Ben