As stated previously I used Fusion 360 to design the parts. I have linked all the designs below:

Rotary Tool Mount

X End Stop

Y End Stop

Z End Stop

The process I took to design the Rotary Tool mount was first to exactly copy the dimensions of the existing part. I used a digital caliper for this. Then I printed a couple versions until the dimensions were right. 

Then I started to experiment with the mounting and really like the dovetail style slot with the bolt holes to secure it more.

After I printed the z mount I proceed to design the laser mount. I measured the dimensions of my laser and made a basic mount that can slide into the dovetail. Once I got the tolerances right I was happy to proceed with the next stage of the design.

The next stage was making the mount for the rotary tool. I knew I wanted the tool to screw into the mount as this would be the most secure. So I started by designing and printing a few screw threads until I got the best one. Then I added the dovetail mount and printed it. This version did not have a support for the top part of the rotary tool and this resulted in a large bending moment. I did suspect this would happen so I added in a z-stabaliser. This worked well.

Now that the machine was working well I did not want to destroy it! So it was time for the end stops. I measured the approximate distance between the two smooth rods on the x axis and tried to design something that would clip on to it. It took a couple prints but I got it right. Same process for the z mount. Since the same design was not going to work for the y axis I had  to go back to the drawing board. I ended up using the limit switch in a different orientation but was still happy with the result. I had to design it to bolt on to the 2020 aluminium tubes. This was simple because I only needed to create a bolt hole for the mounting bolt.