First, and Foremost model links are not always hosted by reliable servers and such. This may cause temporary links or very slow ones at the least.
Old files such as 5month old models, might have been taken off the webserver due to: Popularity, webspace, or the host is dead, or non-existant.
Solution to these Dead LInks and files, is to PM the author the model, creation or whatever it might be. Post on threads over 5 months old is probably NOT in your best interest, unless you want to get flamed.
Your best shot is Private Messaging the author and asking them to give it to you personally. Or you can get most of the old files at www.thrill2kill.com (No im not flaming, they have every file) Or ask Nsmodeling.com, Nsarmslab.com, Hivesight.com
So check the guidelines before reviving dead topics and giving everyone a heart attack! Models do not live forever, most of the older models are non-popular models have been replaced and outdone by the newer models, so you might want to check those ones that exist and are prepared for your liking. Use these guidlines if you OMG h4x HAVE to have them.