THEY'RE ASKING FOR IT!!!
Here's my opinion on it man, you've got 2 choices, first, you tell them up front that they've got the model wrong on the 7620 and take whatever happens price wise, but, $1021 Canadian is pretty average on that guitar. *At Axe music in Calgary, they are regularly $949.99 so that is something of more value to take to a music store owner than hey man, that's the wrong model ###.
Your second choice is, if that is a very good price for that guitar in that store (I know things usually are more expensive down east than out here) then buy it and don't say anything to the store. *If they figure it out, fine, but if you buy it and then rub it in their faces that they screwed up, you probably won't ever get another deal out of the place never mind if you ever try to get a service or anything done there.
Sometimes, as I heard once, it's better to take the money and run, so to speak, not stand around and ask questions.
I really hope you get this guitar, it's obvious you want one bad enough. *Good luck on getting it man!