This thread talks about character meshes, but the beginning of Caliente8's reply ought to help you regarding preparing skyrim .nif files so it can be loaded onto blender 2.49b, saved as a (2.49b) .blend file, and accessed in blender 2.62. If 2.62 blend files can be loaded into blender 2.75, then after loading the objects from the (2.49b) .blend file into blender 2.62 and saving that, you can load your (2.62) .blend file into blender 2.75. When you're done, you'll have to load it backwards from blender 2.75, into blender 2.62, and finally into blender 2.49b, because you need 2.49b to export a valid .nif file, and even then you'll have to prepare it for skyrim before you test it in-game.
You need Nifskope to prepare the .nif file for blender use, and to prepare your modified .nif file for skyrim in-game use. Some people use Blender 2.49b all through out their process, but some are more comfortable with newer UI and better tools of newer Blenders so they go back and forth of the Blender versions.
*The preparation of the .nif files as instructed in the thread are for body replacers (I think) and armors follow the same preparations. Google what are the appropriate blender actions you should take before you finally export your modified .nif file.
*I'm no blender/modding expert, I can only barely use blender to be honest, please make use of documentations such as Blender 3D: Noob to Pro. Google stuff, watch/read tutorials, etc etc
*Take this reply with a grain of salt. Again, I'm not a blender expert.
*Read the thread I linked because I didn't really explain how blender version works in the most sensical way I admit.
*Sorry for the run-on sentences.
How to Install Blender 2.49b: What You Need (Windows Installation)
^That's how I installed Blender 2.49b on my laptop. Should be pretty straightforward. Uninstall any Blender on your system before attempting to follow those^ instructions!
For my later versions of blender (anything after 2.49b version), I choose to download the ZIP option over the MSI option from Blender's website to avoid conflicts. For example, in C:\Apps I have a folder named 2.62, which is where I extracted the contents of blender-2.62-release-windows64.7z (Blender 2.62 ZIP (technically not a .zip file, aha)). I can run Blender 2.62 with no problems and Blender 2.49b is not acting up in the presence of another Blender in the same drive. Easy peasy.
Hope this helps!