[Kube]

You will find differing opinions, as you'd suggested, as to whether or not you "need" the filter. I, for one, don't believe they do enough to warrant their necessity.
You may remove the entire filter assembly. And yes, a simply plug at the back of the block will do the trick.
Don't forget to plug the return boss as well. On your '46, that should be directly next to the dip stick tube at the oil pan.
Oil filters were optional until early 1946. That fact may help ease your mind...