Hi George,
I don't have a Corbin, but the bumpers may be able to be softened with a hair dryer. I use them for removing stickers, reflectors, etc. Or sit the pillion in direct sunlight upside down for an hour - the bumpers should be as soft as they're gonna get by then. Then have your bride sit on it when you're ready to insert bolt.
I am sure you'll get some better answers from experienced Corbin owners soon. Another thing you could do is mount bags on an EZBracket - but then again there's another $120-$150 out the window.
Ride Safe,
Dennis
