Be a bit leery about cellaring rectangular tins like those by Germain, Penzance style tins. They tend to lose their seal for whatever reason. Have not had that issue with my Mac Baren tins, thankfully. Solani tins are a bit suspect as well. Their 100g tins have the tobacco just stored in a plastic bag, the last tins of 633 I opened were really on the dry side. The smaller, 50g tins had issues as well. I opened some decade old 633 and all had rust on the inside, probably b/c the flakes were so moist.
I've taken to using Bell jars. I just microwave the jars for a minute or so, put in the tobacco and seal em. As they cool, they create a slight seal.