Grolsch bottle seals

I scored 13 grolsch bottles at a yard sale for $4 (i'm pretty thrilled about that), but a lot of the rubber seals are dried out and two are missing. I work at a hardware store, so I can get o-rings for almost nothing. Would one of those seal it well in the long-run? I haven't used grolsch bottles for anything, so i'm not sure what I should expect as far as longevity for the seal.

Also, do they still make them with ceramic tops? I've only seen them with plastic tops (not grolsch brands, but the same style), but mine are ceramic. I'm just curious.

I can't speak to the ceramic/plastic issue, but I do know that there's homebrew supply websites that sell that Grolsch replacement seals. I don't remember which one, since I'm still deployed and the only thing that I can do is shop and browse every home brew site on the planet.

Buy the right gaskets for your bottles.
They aren't that expensive and they work the way they are intended.

You can get a pack of 100 for about the same price as crown caps.

I know you are thinking..."Hey, I only have 13 bottles, why do I need a hundred gaskets????"

Trust me, you will be getting more bottles in the future.
Once you buy a few...then you want more...then you want even more...etc.
That's why I have 13 cases of Grolsch bottles.

I've found that the gaskets become flatter after being used a few times and don't seal as well. I instituted a policy of replacing the rubber after every filling. I'm sure it is a bit paranoid, but the cost to ensure a good bottle is minimal.

I bought a bag of these for my Ikea swing tops. Replace every few uses.

http://www.northernbrewer.com/shop/grolsch-gaskets.html

I'd use the "o" rings. Other than cosmetic appeal there is no reason they won't work for beer. Every faucet in your house has them in it.