Im looking for a narrow barrel band for a Western Field 30-30. Anyone have any leads on where I can find one or have one willing to sell?

Try asking on Marlin owners forum.

If that's the Mossberg 472/479 Model 30-30 rifle.
Try Havlin Sales
they list some parts for the Mossberg Models.
I don't know if the WesternField (MontgomeryWard) rifles were different as far as the bands were concerned)
https://havlinsales.com/order.htm
https://www.havlinsales.com/center.htm

Numrich shows the Mossberg models but the rear band Out of Stock
The front band is in stock.
The WesternField Model they just cross reference to the Mossberg Models.

https://www.gunpartscorp.com/g...fles-mossberg/472pca