Bearings, seals and brake covers, o-ring!

[thatguy]

So I guess my first post in the real forum is gonna be a stupid question...

I got bearings and seals online for my 200m (same rear as 200e) and it came with a 3rd seal. I know its for the brake cover and thats why I got this one, but I can't, for the life of me (or the life of my trike), figure out how it goes on. It makes a nice seal around the brake rotor (better than the stock seal that sits inside the brake cover), but it does not fit inside the cover or outside. I have knocked the stock seal out of the cover and it is way too small to replace that one. The brake cover wont fit on with the seal inside and the axle nuts cant go on with the seal on the outside of the cover. The outside diameter of the 3rd seal is the same as the other seals, but it is a different shape and fits nicely around the rotor nipple thing. Did they include the wrong size? Can I just go without it and continue using the stock one (its not snug at all on the rotor)? <pics below>

Also, I need an o-ring to go between the rotor and axle, anyone know the size on this? I assume I could get it online at a general supply retailer..?

I appreciate all the help guys!