If you want to unfold the files and risk building them only to find they are not proportional to fit a human being, sure:
(All this is in my 3D model thread)
SPI Forearm.
Download here:
http://www.4shared.com/file/LP47n2AF/SPI_Forearm.html
-----------------------------------------------------------------------------------
SPI Knee.
Download here:
http://www.4shared.com/file/jYxW393z/SPI_Knee.html
***Note: there is a difference in the actual knee file from the pictured one. In the file, there is an arrow colored on it. It is there to point to the bottom of the knee.***
-----------------------------------------------------------------------------------
Chest Piece.
http://www.4shared.com/file/w7d8yuic/SPI_Chest.html
-----------------------------------------------------------------------------------
Bicep. Not the final picture, but should resemble the file somewhat.
http://www.4shared.com/file/Es8Zmiu_/SPI_Bicep.html
-----------------------------------------------------------------------------------
Just so you know, there is no true canon as far as SPI armor goes, because there are so many different concepts, so some stuff may not look right but is actually either from a different picture or a combination of multiple ones. But anyways, it would be pretty cool if you built these...