Art,
this is a Singer UFA which stood for Universal Feed Arm, the original name for the shoe patcher. Singer began building these machines in 1883. In 1896, the changed the name of the machine to a 29 class as they did with most machines. They went from names to numbers for the machines and subclasses. Your's is a UFA and it uses the same bobbins , needles and hook as any 29 class. Yours even has the old style bobbin winder. Hope that helps.