target holder on the back of pistol boxes?

So I've seen some target holders for repair centers on the back of some folks' pistol boxes.  Is this some sort of add on?  If so, where do get one?  I just got a Strong Box and thought it'd be nice to have.

Don't know if this is what you had in mind, but this is my repair center and brass-defector-screens holder.  I only use it to hold repair centers when I am training/practicing.  No need to hold repair centers at a match.
 
Mine is home made.  I went to a big box home improvement store and had them cut a piece of acrylic to my dimensions.  I also bought six bolts, nuts and the white plastic spacers you see.  The size of the acrylic depends on your box.  But you don't want it so high that when you drop your targets you cannot reach them to pull them out.  How long you want the plastic spacers depends on how much stuff you want to hold.
 
The board you see separating the screens from the targets is to prevent the metal screens from tearing the paper targets.  The slot cut in the board is so I can easily grab the targets.
 
On my first attempt I purchased the cheapest acrylic they sold.  Mistake.  It cracked on the first trip to the range.  I then purchased the most expensive acrylic they sold.  That was a few years ago and it is working fine.

That's exactly the sort of thing I'm talking about.  Thanks for the idea!  Anyone have any different takes on this concept?

I have a brass catcher mounted to the back of my Strong Case using one of their their mounts. This seems to preclude carrying targets there also, unless someone has a brilliant idea.

What about cool ideas for brass catchers?

I could never make that work for me. I would always need something I didn't have. Or I grabbed the wrong box. Like Joytoshoot said You don't need to take any to a match. My idea was to just grab a neat computer bag and fill it full of targets. Separator works pretty good to help find things. I keep 50' targets on one side keeping the sf and tf divided by some full size targets folded to fit. On the other side I have the 50yd targets and 25yd targets separated the same way and also have 25yd reduced targets. I use the extra pouch to hold an extra stapler, staples, pens and spare magazines for my most used pistols. Like I said you never know what your going to forget. The bag also has enough room to drop a couple of pistols in if your running out of room. That's my different perspective on carrying targets.

On the Strong box with the brass catcher, depending on how you fold the net you will have enough room for a somewhat large size stiff cardboard envelope.  The targets will fit in this envelope and the brass catcher bracket will keep the envelope from falling out.

I use Velcro to hold my screen against the back of the box.  there is some room for a few targets but I usually carry practice targets in a briefcase with stapler.