[ARC5] Weird transformer

[Kenneth G. Gordon]

I have what is supposed to be an ARC-5 audio transformer, but testing 
with an ohmmeter returns strange results.

It has 5 terminals on top, labled 1, 3, 4 on one side and 6, 7 on the 
other. There is no bracket for a neon bulb either, nor any place to 
solder one.

The number on the side is ES-691026

As I remember it, real "ARC-5" audio transformers are ES-691027

So, does anyone know what this is?

I suspect it came from an ARC Type 12, but am not sure.

Ken W7EKB