Have a 61-261 with a stock oil bath air filter that has the appearance of the old style Navy white beanie hats for lack of a better description or p/n ( sorry 'bout that). Removed the old fiber cartridge and dropped in a Wix # 46192 pleated element for a perfect fit and absolutely no change in outright physical appearance. Not to plug Wix, but they have a catalogue on their website that has hundreds of filters catagorized by height first, then od, then id. Just measure the cavity left by the old element then go down the list till numbers match or close thereto. You want to make sure the element fits hard against the top and bottom of the housing for a good seal, and id and od gives good air flow into the carb air horn. My element was a little pricy at $15 but my ride is worth it. I did notice the the element is rated at 85 cfm and an online widget says my engine gulps 165 cfm at 60 mph, but in road testing the thing I didn't find any deterioration in vac readings, idle, low or 60 mph white knuckle speed for me.
