This is an older motherboard, making it hard for me to obtain this IO shield. Is there any place I can get one?
You might get lucky and find one on that auction site: IO I/O shield backplate for PC mainboard motherboard ASUS, ABIT, GIGABYTE etc. | eBay
The above link is provided for your convenience.
These shields used to be available on Click Intel to Purchase Computer Spare Parts and Technology Books but they do not seem to be available there now.