I've uploaded two short videos of me performing the cadenzas on the "Cadenzas for Mozart concertos" page below the pdf files. The quality of my built in imac microphone isn't optimal but it should be good enough to give you a good idea!.
Of course you are free to perform them differently or modify them if you want.
I am associate principal horn of the Singapore Symphony Orchestra and the author of the progressive methods. I'm happy to share my experience as a horn player and teacher with you.