gunnar,
I don't know if you've already done the deed yet but I would not jar that aged tobacco.
As far as I am concerned, aged tobacco is meant to be consumed ASAP after you open the tin.
If you open that tin up now, the aging process will be finished and you would benefit most from smoking through the contents fairly quickly. I hear that aged tobacco goes downhill pretty fast...
If there's a problem with your Pelican/Kingfisher tins, then it is a moot point now because they've been stored in them for 10 years already. If they were ever going to rust or lose their seal, it'd probably happen by now so there is nothing to gain by transferring the tobacco to glass at this late stage...
I assumed (somewhat wrongly, it turns out) that you were dealing with fresh tobacco. (Or in the case of Kingfisher, a recent tinning that's about 1-2 years old)
PS to Lyle: Rust will render a tobacco unsmokeable if it penetrates the interior. I sure wouldn't want a metallic tang in my smoke! It's probably not the healthiest, either...
I don't know what the solution is when dealing with aged tins. It's more of a luck of the draw thing. Jarring, though, should be done as soon as you acquire new stock so that your risks of tin failure are minimized. A small percentage of tins will probably always be flawed, but that's the risk we take. It helps to buy in multiples as savvy wine consumers know. It is heartbreaking to hear of someone who selected a single bottle of expensive wine to save for a special occasion only to find out 10-15 years later that it was corked! The only insurance policy is to buy a case. (I know that is not relevant in Gunnar's particular case, but it is a disclaimer to everyone else: if you only have one tin of something you treasure, you'd better hope that tin is in immaculate condition or you may be very disappointed down the road!)