Somehow, I owned this car for two weeks before I realized it had a screw on canister oil filter, which was not from the factory. I snapped some blurry pictures from a blind angle up under the rear of the car to try and find some more details.
It appears to be an Empi Full Flow Filter Oil Pump (Amazon link), though there are a variety of different brands in slightly different styles available. This one most closely resembles the Empi, from what I can see.
There is an old, rusted oil filter on there. Lots of rust around the edge of the canister. It has been on there a while. Hopefully, there were other oil changes done without changing the filter.
I’m pretty sure the oil sump cover with drain plug is an after market add-on as well. I haven’t found a definitive answer as to whether or not this car actually came with a drain plug or only the outside sump cover which is removed to drain the oil.