Hi Joe,
You hit on the limitation of the MY1014 needle in that the largest needle size available is 14. Whether this needle in a size 16 or 18 would have worked like the original 127x1 is unknown.
Your needle orientation is correct, scarf to the left. I noticed a non groove "island" above the scarf in my Organ sz 14 so that the thread will form a loop. Why the needle is designed with the grooves on both sides is puzzling, though it must have something to do with the industrial machine it was designed for.
My feeling that the solution to overcome the limitations of the MY1014 needle other than using 127x1 or a different machine would be to search for a more suitable replacement needle. I often see the packs of Simanco industrial needles selling for $5 per 100 for some ancient industrial of days gone by. Perhaps one of these sizes will be "goodenough" though this is not very helpful for today.
Jon