There are no downloadable patches for MW2 (legit version)
All the patching is being done by steam and it are very tiny files (considering they take 10 seconds to download and patch), but theres never like a file you can download. (Like 1.1, 1.2, 1.3, 1.4, 1.5, 1.6 and 1.7 on CoD4).
So in that case I'm sorry. Also I lost my iw4mp non-console :P