The answer is: 50 cents worth of thin gasket sheet and a ball pein hammer.
Place the sheet of gasket material on the pump housing and tap lightly with the ball end of the hammer. Go around the outline of the pump face and one tap in each one of the holes. If you do it right, you'll have a gasket that only needs a little trimming with an exacto knife. The ball end of the hammer cuts the gasket to shape and if done correctly, won't damage the pump. I have used this method for years and it works great.
Place the sheet of gasket material on the pump housing and tap lightly with the ball end of the hammer. Go around the outline of the pump face and one tap in each one of the holes. If you do it right, you'll have a gasket that only needs a little trimming with an exacto knife. The ball end of the hammer cuts the gasket to shape and if done correctly, won't damage the pump. I have used this method for years and it works great.