Hi all,
As an addition to my collection I recently got a 2465 that had the rubber/plastic ribbed pad as well.
The cut-out in the material to me makes it a TekTronix original, especially because it keeps the ventilation holes exactly free.
It either serves as extra protection for the bottom, and by doing that extra protection for the interior electronics,
it also can be a saveguard that prevents the ventilation holes to be blocked when stacking devices, as people often do.
Some pictures here:
/g/TekScopes/album?id=89635Un saludo,
Leo