It appears to be a Gritzner. They are some of the best machines ever made. I parted one out a few years ago for spare parts for a friend. It appears to be the same model. If so, there is a grease pot under the needle area. It's a square metal "box" directly under the needle, if I remember correctly. It was depleted and the old grease was hard and dark. I would remove that box, clean it out and refill it with Vaseline. (Others might have an alternative sewing machine grease suggestion, as this one is the one I use for Singer machines.)
If it has that box, it's about 1.5 inches square and about an inch or inch and a half deep.
bkay