It is a Singer Model 66 Redeye. You can get a free manual download at ISMACS.com. This is the machine I would like to find for my DGD. They are virtually indestructible and parts are widely available. They go from $30 to over $100, depending on condition. This was a treadle originally and there is probably a flat metal plate on the light, which goes under the round, embossed plate on the back. Probably needs adjusting. If it runs and sews, you probably have a durable machine. Let your pocketbook be your guide.