I'm a little confused on why the notch is needed. Is it to get the old bulb out or so the new one fits? It kinda looked like the pins didn't exactly match but the angle in the side-by-side pic wasn't too clear for me.
Thanks for this tut tho! Very helpful to not get screwed on the bulbs!
add: btw, here's a pdf of your invoice that can't be "cleaned" to show your info.