NiaJane, the best advice I can give about the Singer Slants is to go to the Groups section of Yahoo and join the Singer Slant Group. There is lots of advice and in the Files section there are manuals and plenty of help.
Also, you'll find that many recommend TriFLow oil for vintage machines. It can be found at bicycle shops. Regular sewing machine oil is good, but TriFlow has tiny flakes of Teflon in it, which help protect the parts from wear. You can also find grease with Teflon, for the gears.
Best of luck finding your Rocketeer.
Tate