Come to think of it, there are. They're on page 98 (aka the part of the rulebook most Seneschals just end up ad-hocing, except for falling damage, since people usually only get into RoS for the combat). I will reproduce them here.
|Age||Age Category||Aging Target Number|
|45-49||Early Middle Years||8|
|50-54||Late Middle Years||9|
As to losing attribute points...
|Number of Successes||Attribute Points Lost|
So once you reach 40, every year you roll HT against the TN for your age category. If you're particularly unlucky, a fumble could mean that the moment you hit the age of forty you suffer from a critical case of old age and lose 10 points worth of attributes.
For a sorcerer, I would also have them make that roll every time they age after casting a spell once they're past 40 (although any attributes lost due to unnatural aging would be temporary, attribute points recovering at a rate of 1 point a week, as opposed to the permanent loss from one of the once-a-year aging checks. But that's just me).