My Regal's, (yeah, here we go again with Tweed's *$%*$%! Regal...), bridge slides right out of the groove on the biscuit. It's made out hard maple they say. They also say that if you replace it with bone or ivory that the sound will be too tinny, but I'm tempted to check it out anyhow, just to see what it does to the tone.
Grab's right, you oughta replace the bridge, unless you could mebbe super glue a wood shim to the bottom of the bridge (not the biscuit) and sand or file off any extra so it slides back in neatly. Here's a recent post regarding reso bridge tips from a resowizard from Hawaii. He flips the bridge completely over and...well here...
CocoJo's Reso Tips