This Fireside issue has me confused

[Jerry B.]

Of course a sloppy belt can always cause problems. But the mandrel on any combination machine runs at the same speed in both two and four minute mode. The gearing changes the speed of the feed screw which slows the speed of the carriage as it travels across a four minute cylinder.

Jerry Blais

[Phonofolks]

Is this a Fireside Model A or Model B? The reason I ask is that I have a Fireside B that someone removed the 4 minute half nut so the gear can be moved to play 2 minute records.