  An analogue of the correspondence between GL(k)-conjugacy classes of
matricial polynomials and line bundles is given for K-conjugacy classes, where
K is one of the following: maximal parabolic, maximal torus, GL(k-1) embedded
diagonally. The generalised Legendre transform construction of hyperkaehler
metrics is studied further, showing that many known hyperkaehler metrics
(including the ones on coadjoint orbits) arise in this way, and giving a large
class of new (pseudo-)hyperkaehler metrics, analogous to monopole metrics.
