It's a drop-in bobbin/horizontal rotary hook. Under the needle plate, you can oil in the center hole under the bobbin basket and the feed dog joints. You can also oil the take-up linkages, through the slot in the front of the machine. There aren't any service panels on that machine, so when it wears out, throw it away and get a new one. I've got pictures on my blog, but I'm not allowed to post my blog links.