Within the new Spitfire Symphony Orchestra library there is a folder called "Legacy" which contains the old patches from the Spitfire Symphonic Strings/Winds/Brass/Percussion libraries with their original interface.
However if you load the library from the "Browser View" of Kontakt 7, the top of the list will default to the "Legacy" patches. This is indicated by the "a - " at the start of the Horn Solo patches, which increases alphabetically.
If you wish to use the Browser view then opening the specific "bank" that you're after will allow you to load the correct patches. To open the bank selection click the drop down menu above the preset list.
From here you can specify that you want to go into the "Symphonic Brass" folder. Below the selection is the "Symphonic Brass > All Sub Banks" option to look at all the patches present in the Brass section, and these patches will load with the new GUI.
If you're still having trouble with this please get in touch using the support widget on the bottom right corner of this page.