Here is the finished product.

Right off the bat, this is not the best matty trap holster, It works for me, and cost 6.00 to build + odds and ends I had around the house. It will easily survive this weekend, maybe longer. If you want a professional and awesome looking one, look up jme1979. He has a nice one. I just jumped on the wagon too late to buy one before Halloween.
There are NO TRAP MODS in this build. I refuse to put a v-hook on my trap.
Total Build Time: 1-1/2 hours + (30 minutes at wallyworld)
Materials:
About 1 Square foot of Vinyl/pleather
1 Medical style hard board folder
1 small straight bracket
Hot Glue and a Hit Glue Gun
about 16" of strap material ($1.00 wallyworld)
1 Pair heavy duty snaps(4.00 wallyworld)
1 Hanger
7 Pop rivets (i used 3/16")
7 washers (1.00 wally world)
Lighter
Drill
First I found a template of the shape of the original holster (search is your friend). I re-sized the template to be correct dimensions 6-1/2 long. The width was proportionate to the length. I printed it in card stock(but regular paper should be fine)
I cut out the template and then took my medical folder and traced the template twice. Then I cut them out.
I grabbed my pleather material and measured about 1/2-3/4 in all the way around each template and cut the shape out.
I made cuts in the pleather so it would wrap nicely around the curved edges and hot glued the material to the cutouts. After, I hot glued the bracket to one side of the holster.
Next I cut a short section of strap and installed a snap into it. I grabbed the Matty Trap and wrapped the remaining strap around it and then cut it to the desired length. I installed the other part of the snap on the longer strap. I took a lighter and melted the ends of the strap. I also melted the strap a little too to make it tougher.
DO NOT FORGET TO MELT THE STRAP ENDS of your snaps will tear out of the strap.

OK more than 1/2 way done!
I took my drill and put holes in the places where the rivets will go. I glued the holster together and put the rivets in. I ran the rivets through each of the strap ends to hold them securely.

To prevent tearing the holder when riveting, I used the washers. Now for some reason 3 of the 7 rivets broke off weird and I had to grab my Dremel and cut the excess off. Once riveted, Your just about done.

Thread your belt through the holster and to a trial hang of the Matty Trap. (I removed the actual trap and pedal and kept the carriage to make it as light as possible)
After a trial hang, I measured the length that it hung and grabbed an old hanger and bent it up to hook the lower wheels and fold over the belt so that the weight of the trap was supported by my belt and not the snap strap. That's it you're done!

My wife was asleep so no picture of the whole thing, but I did wear it for about 20 minutes and walked up and down the stairs in our house with no issues. Feel free to modify this as you like and please post if you try this.
Good luck!