[KevA]

All P Model 7R's are the same Sprocket Hub.

 

[KevA]

View attachment 21972 I stand corrected I guess

Looks to me like an old race is stuck to your carrier, if that's the case it will be preventing insertion how far off is it? Your carrier shouldn't have anything between the hub and its aluminum body. Either intentionally or unintentionally it looks like someone has left old races in there 2x.because I see 3 defined lips here.

Jeez man you need to stop trying to help people with problems as your obviously Guessing rather than giving pertinent advice.
Fuck all goes in this side except a Spacer (Not shown) and the Wheel Hub, The Bearing for the sprocket carrier is fitted the other side clearly shown in the op's image #5.

 

[KevA]

Look at the gadum picture you **. Its flipping obvious that there's a race still in there you ignoramus

 

[KevA]

Live, Learn and carry on