Sorry for the delay, I was on vacation.
Don't shoot the messenger but the Book value of a 100% un-fired Defender is 865$.
I'm not sure what "curio grade" means, (no mention in the Book) but I'd take the 1K$ in a heartbeat if I was you.
I can get that same NIB gun here for <1K$ OTD.
If you got 1.1K$ for it, I'd keep an eye over your shoulder for a while!