[Ron Ramirez]

Hi Wilbur,

6672-N is the same as part no. 6672. The letter suffix indicated the actual manufacturer of the transformer or choke. "J" stood for Jefferson Transformer Corp. I do not know what "N" stood for.

Here is a drawing of the transformer connections:

   

Notice the wire which is identified as terminal 4. Notice also in your photo how that wire connects to terminal 9 which is correct.

From the model 15 service data, a chart identifying the terminals:

   

I hope this helps.

Ron