Different methods result in different final shape.
I do not have Solidworks here (so I couldn't open your models).
Here follows the process I used in Inventor. Should be the same...
Revolve this "D"-shape [using the dia.40, R12 and R20 dimensions]
Make this sweep path [using the R15 dimension]
Cut this from the solid [using the R10 dimension]
Pattern this new cut 4 places 360° [4 slots]
Drill concentric hole [using dia.16 dimension]
Fillet the edges of this hole [using R0,8 dimension]
This will leave you with only the 23,9 dimension, which when you measure the two opposite faces will be close to what is left...