I had already found a couple old cool looking oil lamps in a room above one of the vaults.

.- Was the tenant aware the barrel contained oil?

It turns out that it's an old mining/railroad town, and the railroad or the mining company, I forget which, had easements from way back when the town was formed, under the ground of the town, so we wouldn't have owned any minerals or water or whatever under the property.And, they had the right to come and start digging under the house and yard if they ever decided they wanted to, or to drill for water. 

As crazy as it seems Ford used vegetable oil during the production of their wire insulation a few years back.

I always embed hardware cloth into the hole for good measure before foaming it.If you catch one in a glue board, you can use vegetable oil to free it once outside without harming it.I've always used the snap traps with PB as @Victor S. suggests, but the most important thing is to find their means of access and block that. 

I would give them a few very safe electric space heaters until they buy their oil.

If hardware is not a bad style just paint it with oil rubbed bronze spray paint.

Our area is hit hard by low oil price and there are recent layoffs in the nearby hospitals too.

My husband's W2 job is in the oil business, we give $25 gas cards.  

Im looking into getting an oil boiler (9-10yrs old) converted to a gas boiler.