I remembered seeing the post-card engine somewhere. I don't know who made it, though I have my suspicions. The "Hero" "Ajax" and "Empire" engines are featured in the 1880 Ives, Blakeslee & Co. catalog. There are accessories on page 106, and The steam engines are on pages 105-107. The Ajax is on page 106. Price is $10/doz.
Thanks Charlie for jogging my memory. BTW, the price for the Hero has doubled from the ad you sent.