I’m pretty sure I did something like that on the 200. Also look at any rust stains or corrosion to try and help match it up correctly. You can do it!
That ’65 200 I had was the Mother Of All Mercs and came straight from hell. I never did get it going and I would have gladly paid the guy who bought it just to get it out of here. 
All I have left are some photos.
I guess there is something for everyone, because I love the 200’s from the 60’s I am building a 64 now, and really need to find a lower unit that I can rebuild. It must be for 63-65. Anyone have one?
Glad the photo was posted. I would have taken a photo of my 200, but not sure if the relation to the key is the same. Really, you need the magnets to be near the #1 coil when the points open. Shouldn’t be too hard to figure out.
Steve