Steve, I agree with George, except that his guess wasn't wild. I doubt that a '33 'Sit Up & Rear Back' lathe would have sported a jawed chuck so most probably the accessory is a faceplate (multi-screw chuck). Of course, like me, down thru the years it's had lots of ? upgrades & add-ons. :)
If there is no set screw then the spindle is threaded and the faceplate was screwed on. If it's inboard remove by turning CCW as you face the headstock. Early hobby lathe outboard spindles were threaded left-hand so reverse if your faceplate is outboard.
Soak thoroughly with WD40, rap the hub smartly several times and leave over nite. soak again, & rap. Use a strap or pipe wrench or bolt a striking bar to the faceplate for leverage. Loosen with 1 or 2 hard hammer blows, not several soft taps. If AEF, heat the face plate (torch), cool the spindle (dry ice) and try, try again.
If your faceplate is inboard, you should be able to move the spindle forward enough to change belts, but be sure to loosen the pulleys and remove the outboard fasteners. Don't forget the advantages of link belts, especially if your lathe has sleeve bearings..
Steve, From your query, I think you know all this. I answered with this long reply mostly to help true newbies.
Turn to Safety, Arch Fortiter
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