Hey Tommy,
Are you asking how to go about finding and layering these two sounds? This can be a good exercise and help "jump start" the learning curve.
What you can do (we'll provide a step-by-step below) is start with an Initialized Performance... then search and select a first Part, then add a second Part. Then you can begin tweaking them into a playable layered Performance...
Start with an initialized Part.
From the PERFORMANCE (HOME) screen
Press [CATEGORY SEARCH]
Select "Init"
Select "INIT Normal (AWM2)"
Press [ENTER] to return to the main HOME screen.
This sets up a Single Part with an initialized Waveform assigned (0001)... this default happens to be an acoustic piano Waveform with an immediate attack, full Sustain, immediate release. What we'll do is replace this with a Harp program from Montage's extensive Library of instruments.
In the screen touch the TYPE/Name box for Part 1, a pop-in menu will appear touch "SEARCH"
The "Part 1 - Category Search" screen will appear
Set the BANK to "Preset"
Set the ATTRIBUTE to "Single"
If you touch the box with the magnifying glass you can type in the letters "harp" to view sounds with those letters in the name
Set Main to "All"
You should receive about a page and a half of results... move the cursor to highlight and Audition each as you desire. When you decide on one, press [ENTER] to return to the main screen
Next we'll literally "+" add a new Part, search for the second tone... you can "audition" candidate sounds while searching.
Press the "+" ADD symbol to Category Search for your second sound. Don't limit yourself to just fretless basses, remember in the Clavinova they needed to be creative by pulling together two rather bread&butter sounds to build a unique tone... you literally have hundreds of choice.
You may want to take the time to read through the short article on
MONTAGE: Using Category Search, as this becomes an important skill in navigating the Montage. It will cover the three main types of sound Searches.. and explain that Blue listings are Multiple Parts, and Green are Single Parts.
As you begin to try new sounds for Part 2...In the lower left corner, you have Mute options: it is possible to MUTE the ORG (original) letting you listen to only the sound you are ADDing, or you can MUTE the ADD, letting you hear just your original tone.
Once you have layered these two Parts you can begin to tweak and make them work together. Take your time.
Hope that gets you started, even if it does not get you close to the original "Clavinova Tone".