A904 Cooler Line

I have a 63 Valiant with a 225 slant six bolted to a 904 torqueflite. Just below the starter motor, on the transmission cooler line, is a metal canister about 3/4 the size of a beer can that is attached to the trans cooler line with threaded, flared fittings, male on one side, female on the other. It is held in place with a wire hoop that is attached to the bracket that is bolted on. Everything is completely rusted, so it has been on the car a long time.

I cannot find any information as to what this is and if it was original to the car.

I am guessing it is an external filter, but not sure. Since the transmission also has an internal filter, not sure why it would be there. Could it be some sort of accumulator or extra reservoir for some purpose?

I have had some trouble with the trans, and contemplating removing it, if it is a filter, in case it is plugged up.

Does anyone know if this would have been original to the car, or if it could be anything other than a filter?

Thank You!