Hello Matt,
Yes, you can achive an automotive quality finish using Rustoleum enamel & a brush. Rustoleum won't tell you this but there is a hardener made by Majic that will work with Rustoleum that makes the finish hard enough to color sand & rub out. Another key is to use enamel reducer (also by Majic) instead of paint thinner or acetone to thin it. You also need to apply many very THIN coats with a squirrel hair brush to build up enough thickness to finish as described above. Rustoleum smoke grey is a very nice color for machine tools. If you need more information please contact me off line & I can go into further detail.
Regards,
Rod Baker