Questions on hollow body bridges

[GlennW]

1) You can see where the bridge used to be. What's a good way to remove the marks? I was thinking about gently wet sanding with 600, but don't want to damage the finish. Any recommendations?

2) The top is about 1/8" thick. Do you think I should put another little support block under the bridge where it is now? You can see where the bridge used to be in relation to the block that's already there. I don't know the history of the bass - how long it's had strings (they look pretty old) or if it was tuned to pitch. I don't want to top to start collapsing from the pressure. I'm not concerned with how it'll alter the sound; moreso with stabilizing.

Thanks a lot.