History

Not sure why they left the market...but could speculate. Case rigs were at one time Ingersoll-Rand rigs and then Tulsa Rig Iron...unique setup with the drillers seat on the other side. Astec purchased American Augers and from there American Augers fell under Ditch Witch....today they both fall under the Toro header.

From what I could research, Tulsa Rig Iron acquired the Ingersoll-Rand's HDD division in 1999 and creating Tulsa Trenchless. In 2005 the company shuttered its other divisions to focus on mud systems. https://www.tulsarigiron.com/history  

CASE and Astec however have a more interesting story. The companies inked a manufacturing and distribution agreement in 2002. https://www.rermag.com/mag/article/20942957/astec-industries-and-case-form-strategic-alliance

What's interesting is that, at that time, Astec owned American Augers which fell under its Astec Underground division. 

Then in 2004, Astec acquired the CASE line as noted in this story from 2005: https://trenchlesstechnology.com/midsize-rigs-making-their-move/ .

Fast forward to 2012 and Astec sold off its Astec Underground division with American Augers and Trencor going to Charles Machine Works, the parent company of Ditch Witch.  https://trenchlesstechnology.com/american-augers-sold-to-charles-machine-works/

At the same time, Astec was looking to completely divest of its underground infrastructure equipment and sold its smaller HDD rigs to Toro. https://trenchlesstechnology.com/the-toro-co-painting-the-underground-construction-market-red/

I surmise that these rigs are the ones that can trace their lineage back to CASE.  

And then, in 2019, things came full circle with The Toro Co. acquiring The Charles Machine Works brands. https://trenchlesstechnology.com/integrating-after-the-acquisition-toro-co-charles-machine-works-moving-forward/