Hi Barra , you have it correct....... the small magnet out in front of my rig is the 4mm magnet that came with the TLE5010 Boards ( at the bottom of the 2nd pic marked 1/2 in blue for North)
The magnet I used in the Rig (yellow lid) is a 3/4" or 19mm Rare Earth magnet I use in the Shop or on my Fridge , I let 2 of them smack together from 4-5 inches away by accident and one of them snap right down the middle (north / south line I don't know? ) but watch for sharp edges if it happens to you. Because with these 19mm R.E. magnets N/S is either side (axially-see pic a few posts back) I believe the two halves snapped together in a N-S-N-S orientation , and because it is reasonably strong it finds North pretty fast in the water bath if you keep it away from the edges.
