Forcing primary alias if multiple aliases per node

Hey,

So I had a bunch of nodes that I updated URL aliases for on my development site, and I moved my development site over to my live site with those URLs. Now that I moved it over and my site is indexed in google, all of my old links are returning dead in search engine returns. This is destroying my page ranking unfortunately. So, I figure I'll just go into the admin alias section and manually update all of my old node aliases to the new system. However, when this happens, the 'new' alias is taken over as the primary one.

I have book pages on outdoor places. We'll use jay peak vermont for example.

My old aliases were like this. http://www.lifeundersun.com/guidebook/jay-peak

My new aliases are like this: http://www.lifeundersun.com/guidebook/vt/skiing/jay-peak

The new ones are far more descriptive and better for search returns, but google hasn't indexed them yet.

My question is this:

How can I force the newer, more descriptive URL alias to be the one that always shows in the address bar, even if lifeundersun.com/guidebook/jay-peak still goes to the node? Yes, I'm aware of a duplicate content problem but it's better than a 404.

Any thoughts would really help me out I am scared of all these dead links.

Thanks!