Congratulations on your purchase! I also have a Model 1000, had it since I was a child. It's a good shotgun, but like ko41 said you'll need to check the piston shock absorber. If the gun has been shot any at all then more than likely it's not in great shape. I believe the original shock absorbers weren't resistant to cleaning lubricants and they turned to goo. The replacement shock absorbers are supposed to be better. So even if the shock absorber in the shotgun looks ok, I would probably go ahead and replace it anyway. I just replaced mine and one in another Model 1000 for someone else. Mine was completely gone with just a black goo in it's place. The other one was still there, but broken into pieces. It's a very easy process. There is a youtube video that shows complete disassembly and reassembly which makes it even easier.
Just curious. Mind if I ask how much you paid for the shotgun?