Ditch Witch SK-500 robot

[mcfluffin]

Hey all,
I'm a student/hobbyist working on a robotics project. I got some tracks relatively cheap from what I'm told was a ditch Witch SK-500 or SK-550 compatible system. I'm trying to make a rover like robot with them. There's a low res picture attached, let me know if more images are useful. The basic problem is I need to get drive sprockets for the robot.
Basically, I'm either looking for a pair of drive sprockets for them or guidance on machining them. I have access to a tabletop CNC which I figure can take care of a lot of the machining work if I couldn't find a pair first. I managed to find some relatively close up pictures of the sprockets from eBay listings and such. Of course if someone here actually had a sprocket and could take a picture of it for my dimensioning, I would be much obliged.
For what I have, I'd estimate there are suppose to be 10 teeth on the sprockets. Of course, if I redesigned them, I could make larger sprockets. I'd imagine smaller ones would put too much stress on the tracks. My tracks say on them "DW 180 X 72 X 39" "(TR logo) TAERYUK" "KS8". If I recall from the numbering system and this lines up from my measurements, there are 39 teeth and they are about 7.2" across. I'm not quite sure what the 180 means though, it seems like they are closer to 110" long.
Any help is much appreciated. Thanks!
Edit: Ditch Witch told me the part number is 140-1085

 

[Timmanny]

Look at WMI INC we build a sod installer running tracks with the same pitch. We are using hydraulic wheel motors run by kubota diesel or kohler gas engines. The 180 is the width in mm. the 72 is pitch from one tooth to next tooth on circumference of sprocket, "pitch", also in mm. And as you realize 39 is the number of "pitches" that make up the track. The sprocket we have made for our application is also a ten tooth. We had in the past made a slightly smaller machine that used a seven tooth sprocket. Just multiply number of teeth you want to use by the pitch of 72. It is not totally that easy but it is a start. Remember that the more teeth you have the faster your machine will try to run. But the more power and torque you will have to have to do so. Our machine is approximately 2500 pounds and also will carry 2500 pounds. With the 25 horsepower kohler gas engine about 7 MPH is about our max speed. We Had sent an 11 tooth sprocket to a customer that had a kubota diesel "26 HP" that did not use the full load capacity of 2500 lbs, but maybe around 700 to 1000 lbs and they said it was fast enough for them. When operating our machine you are in a standing position. It all depends on your machine "ROBOT" weight and what you have to supply power. Hope this is some help to you. I think our company website is WMITSH.com
Thanks,
Tim, over in Mahindra tractors "owning/operating.