Yeah that's it. From TOM'S WIRING GUIDE, Uniden section:
PRESIDENT RADIOS
Models: Washington, Grant XL, Madison
microphone wiring code
Standard 1-Audio,2-Shield,3-Receive, 4- Switching, 5-Transmit
Astatic 1-White,2-Shield,3-Black, 4-Blue, 5-Red
Sadelta 1-White,2-NC...