Very smart,you limit your buying audience when you drain the oil out first.Let whomever Buys em do that,if at all.
So many people emptied out their oil cans in the past,that full ones are few & far between today.
Once you let the original oil out,you can't put it back in. ;)

I'm impressed that they are still full. I have a few and the paper leaks out over time.

I also have a few banks made from these cans. I worked in the Wolf's Head refinery (actually just a packaging plant by then) and they had the special bank lids and would run a few if you asked. ;)