Too bad the DD is eat up. Hopefully the blade is salvageable. I'm starting to think the reason they are so sought after is most of them are have fallen apart by now!

The only two DD's I've seen in the wild with bolsters were both wrecked
One had a busted blade.
Other was rusted through from what I now know is cell rot.

I know you will want to have them shining, but looks like they are solid for the most part.
I'm actually growing fond of horn faux tortoise. I guess I like that they were trying to duplicate tortoise shell even before they were making celluloid scales!