managed to do a couple of metres without a problem
ran into further issues - excuse the lack of terminology
the bottom bit which houses the bobbin stopped moving when the foot pedal was pressed.
diagnosed that at the back the cog had come away from the gear, so pushed it back on and tightened up the grub screws.
that now moves as you'd expect, but the bottom thread just wont pick up. tried multiple times, different materials, re-threading everything but no joy.