CC, you're making me want to work to post longer posts with more useful content, especially when I disagree with you. Unfortunately I don't think I have quite the critical mind you do. But here it goes.

I learned, last year order lights for a Rave (yeah eat one) that if a seller has both an Ebay store, and a website to order from, use the Ebay store because Negative Feedback on Ebay allows you some recourse of action other then talking to your Bank/Credit Card Company about a charge back. I've looked over this Dbags site and I found his eBay account which does already have 1 negative feedback regarding a similar issue here where a customer received an Origin 8 Hub instead of a formula. Personally I'd rather avoid having the Origin 8 name on my bike if I could but thats just a minor quirk.
What bothers me here is the level of responsibility he is taking for shipping the incorrect product. I work for an eBay retailer with both an online store and an eBay store as well and I can't say we've never pulled a stunt similar to this. However in the cases we have if the customer is unhappy, we remedy the situation at no cost because it was our mistake, not the customers.

He did not inform you of the change, I did check his website and he does not have any policies regarding returns, refunds or handling of situations similar to this so really what he's doing is saying "I have your money, if you want it back you need to play by my rules" without ever saying what "my rules" are. Contact your bank or credit card company ASAP, don't mount the wheels. And do this, if you really want to stick it to him.

Get information regarding your buyer protection through the CC company. If they will cover your purchase then you are set. I've been on the other end of these charge backs and they are a PITA to deal with, the CC requests a lot of information and is very finicky with what they receive and how quickly they receive it. If he sent the order via international Priority he may have an even more difficult time just due to the crappy tracking it provides. So if they say

"You're covered, ship the wheels back with tracking and we'll perform a charge back"
You do the following
Box up old weinmans, slap some tracking on them suckers and send them back.
???
Profit.

There is a chance your CC company wont care about the difference, or even give him the option of saying "he sent back the wrong product!" I checked his site and it seems he uses Authorize.net, which is the same Credit Card Processor we use and its very likely he wont get the option and it will be a fiasco trying to handle the situation.

Or Option B. Which is don't be as dirty as I would be.
Send the Wheels back, get your money back and your CC Company will cover you for the costs of shipping. Most companies these days have very strong buyer protection policies, especially in cases where they do not receive what they ordered and the merchant refuses to handle the situation maturely. They have complete control over the money and they will likely just pull the funds out of his account (The funds you paid) and give them back.

I'm not going to argue the morals or ethics hard. What it comes down to is there were no details given regarding incorrect items on receipt, it is clear this seller has done it at least once before and I have a feeling this is a common practice for him. He knew you would have to pay out the arse to return them so he just sent them anyway. I don't say become the white light of justice correcting wrongs, but if you don't want the wheels, stand up for your self and your right as a consumer. People do a lot more to sellers over a lot less, again I know from personal experience. But this is a case in which your rights are getting shafted. If nothing else tell him you want a discount on the set because you did not receive what you ordered, otherwise you'll handle this through your card issuer.

Good luck man.