Coin-op Trade Stimulator published 85 years ago by Groetchen Tool & Mfg.
Impossible to emulate.
21 Vender © 1934 Groetchen.
5-reel Counter Card machine. Last 3 reels are covered, player can play additional coins to buy extra reels (cards) in order to hit 21 hand. Game also features hold buttons.
Click to enlarge
Released in March 1934.
For Amusement Only - Thomas Gustwiller - Taylor Printing - 1995 - Page 155
The Coin Machine Journal - January 1940 issue