GK Persei (1901, the Firework Nebula) is an old but bright nova remnant that offers a chance to probe the physics and kinematics of nova shells. The kinematics in new and archival longslit optical echelle spectra were analysed using the shape software. New imaging from the Aristarchos telescope continues to track the proper motion, extinction and structural evolution of the knots, which have been observed intermittently over several decades. We present for the first time, kinematical constraints on a large faint jet feature, that was previously detected beyond the shell boundary. These observational constraints allow for the generation of models for individual knots, interactions within knot complexes, and the jet feature. Put together, and taking into account dwarf-nova accelerated winds emanating from the central source, these data and models give a deeper insight into the GK Per nova remnant as a whole.