Zito's explanation lines up with what I've found out about ramps. Another use: a friend of mine has a clear poly ramp set betweent the neck pu and the end of the neck of his Rogue. He uses mostly when slapping and popping - it aids in keeping his right hand finger tips closer to the strings when popping. Sounds wierd, but he explains that the string height at that position it too high, even with the action set incredibly low. BTW, his ramp is not fixed but milled expertly to fit snugly in location, this allows him to remove it when cleaning his bass.
ps - Larry, nice looking bass. If thats quilted maple, it's awesome, nice red swirls.
Mike