LES-5 [2866, 1967-066E] in a GEO graveyard orbit.
Confirmation will occur at ~0445 UTC this evening when the satellite should pass through eclipse.
If so this is definitely the oldest emitting GEOsat I know of.
apps.dtic.mil/dtic/tr/fullte…
pscp.tv/w/1mnxeQjQDWaxX