As others have stated, #41 chain is very commonly available in many places. Ottawa is a very large city and will have countless sources. Tractor Supply Co. is known as the Incredible Country Hardware Store in Canada. But this is one place where they won't actually make a chain for you and you can only buy it in a box. I live in a very tiny town but we have two tractor dealers and they will make a chain for you if you tell them the number of links. If you're looking for an effortless solution, this would be the most effortless of all. I simply searched ottawa tractor dealers on google and came up with a huge list of those and similar places that would likely have 41 chain. And I'd be curious to know where you paid $70 for a 415 chinese chain. And you said whoever it was made the chain for you, so if you bought some 41 chain elsewhere, could they not do the same again for you with the new chain? And remember, 415 and 41 are not exactly the same but are close and do work on the same sprockets. And you can't mix links from both size chains. It has to be all 41 or all 415. Most likely, you have links binding and getting caught in that tiny space you pointed out. If you check for binding links with the chain off, you might or might not locate them. They might not bind when the chain's off and lying down but will bind when it's installed. Or vice versa. Either that or it's a loose chain or even both.
