The first test flight discovered a whining noise but no vibration. After talking to Lockwood Tech Support and being told that the noise was likely just slightly overtightened assemblies and that more flight time should cause the whining to fade, I flew another hour. Sure enough, the whining sounds significantly less, almost unnoticeable. Yeeehaaa!
In case you're wondering, the second test flight ended with the pool of gasoline under the engine that resulted from the displaced float guide pin.
Interesting event coincidence, but all is now good.
Alan