Need help identifying barcode encoding from an old form

I have a barcode field on an paper form produced by a legacy AS/400 system that I need to convert to a more modern reporting system. I have been trying to track down the encoding that this barcode field uses, but I have not been able to find anyone with first-hand knowledge of the reporting process.

The system that generates the reports was developed in the mid-1980s as far as I know.

Here is a sample of the barcode in question. There are no alphanumeric fields printed on the report adjacent to the barcode, so I have not been able to do a character-by-character analysis of the encoding so far. I suspect it is Code 39, but I would like to be more confident before proceeding.

Edit

This is an image of my attempt to manually decode using the Code 39 tables.

I just printed and scanned it with an MC9090 and it decodes as a CODE 3 OF 9 with a value of 41031300161002121925.