MR2 steering rack

is it possible to rebuild the MR2 steering rack (SW20 1990 Mk2 (power
steering)) with new seals, recently i have been experiencing strange
behaviour with the steering, it tends to wander, and doesnt always
cetralise, everything else is in A1 condition, ball joints, tyres, wheel
alignment etc, and the car is treated with kid gloves, IE: with great care
so its not the result of a knock etc.
What kind of behaviour would result if one of the power steering seals were
worn, it sometimes feels as though its trying to steer one way or the other
on its own, although this is very slight, but nonetheless cruising at speeds
between 60 - 80mph have now become less controlled.
i can't physically feel any wear in the rack itself, the tie-rods all seems
good as do the steering couplings.
a new steering rack is around £300 uk so i don't want to replace it if i can
avoid it.
secondly, assuming its feasable to rebuild the rack does anyone know where i
can get a seal kit from in the uk, or from the US if shipping is an option.
many thanks for any guidance.
regards.
steve.