Hey Ted and thanks for weighing in! I don't think it's Middletown - the topography doesn't look right for either a northbound or a southbound (and I doubt it's heading up the Berlin branch). Also, the 392 didn't visit the Valley line all too often AFAIK. Hmmm.... maybe heading toward Cedar Hill on the Air Line?
My best guess is that it's on the Midland somewhere east of Hartford. Around Vernon maybe? Or Rockville branch?