I first tried it with the brush attached. The brush does introduce soft swishing noises that are more noticable with headphones. So, as recommended, I removed the brush and readjusted the VTF to 1.25 grams. Now the sound floor is quiet, and all is well!
The AT stylus on my old Sansui turntable was probably decades old, and no longer available. Even the one that AT made to replace it is no longer available. This one fit perfectly and works great.