Not sure if I've already flagged this up but I saw no trace of a path across this field - marked 'private' - to the river. I also suspect the 'river path' here may be almost non-existent.
Everyone heading to or from Brighouse leaves/joins the waterside path at the stone bridge by the second lock.
I recently added a path, leading to the lock on the far side of that bridge, that makes getting a bicycle onto/off the towpath a lot easier.