| Event | SE |
|---|---|
| Narrative | GWMSN Logo - BALPEX 1989 Postmark #1: Hunt Valley, MD — 1989-09-02 Stamp: Letter Carriers, 25 Cents (Scott #2420) |
| Cachet Sponsor | GWMSC |
| Design | Pictorial |
| Scott # | 2420 |
| Stock # | G-89-011 |
| Postmark Type | Special |
| Location | Hunt Valley, MD |
| Owner | GWMSC |