Yes, we had the 'speed changer' one too, aprx 1947.
Its replacement had no gearbox, but the 'mushroom' variable spin pulley. What I can't remember is whether it had a tumble idler or not. I don't think it did, but as before, 1800rpm to tumble speed in one reduction seems a lot.
Apparent, that the innards changed more at times than the cabinet.