You are correct, Greg. As you know, GMC trucks used Hydra-Matic transmission (domestic and military). And, several non-GM vehicles used Hydra-Matic transmissions: non-GM vehicles Kaiser, Fraser, Nash, Hudson, Rolls Royce and Bentley.

1950 Powerglide gear-indicator

1954 Powerglide gear-indicator

1954 Chevrolet truck Hydra-Matic gear indicator