I finally glued the last piece of the M Splitter.. and it works! Marbles roll down it faster than I had hoped, so I considered lowering it.. but there is just enough room for the small marbles to roll under that track and onto the small marble track which has walls on it, if I lower one of the walls.
Unfortunately, that wall is also the support for the track, so it will be tricky to cut. I might have to use the dremel or something..
Oh, so while installing the supports for the M Splitter, the red-and-white headed character knocked over the ramp. Then the character who helped install the ramp fell off the stage where the ramp had been.
Since June 2017, I have spent 4.7+ days on Marble Track 3.
Here is the most recent video snippet. The last bit is from today.