My guess is that you will get wildly different results with this pup on the Dobro, simply because it's designed not to vibrate in just about everywhere except for the spider/cone. Can't put it on the cone directly as it will mass-load the cone to death - literally. Sides of the dobro body should be relatively dead as well from a vibration standpoint.
Well a crazy experimenter like me would try cone attachment anyway. The amount of mass loading might be something that I could live with in order to amplify the thing, after all we're not talking a Dobro King here, we are talking the ability to do one Intro for one song. EQ in the amp would likely make up any difference there.
And if I couldn't easily place it on the cone, then I'd try something like clamping one to the bridge, or even perhaps placing a sheet of that piezo plastic between bridge and cone somewhere.
Heck, I'm crazy enough to try putting a miniature electret condenser element inside the Dobro, pointing at the cone. Attachment? A blob of RTV...
--Mac