Thank for your answers. Due to the nature of our work and why we use this FOG server it’s unfortunately air-gapped from the internet so updates have been hard to come by regularly. The only thing that makes sense on root-cause here was one severely borked imaging operation. Even then I’m grasping at straws for a good answer on what triggered the error.
However, I pushed through our ITsec group and got the server updated to current stable release 1.4.4 this morning which did resolve this error and it’s deploying images normally again.
Thanks for the info guys feel free to revoke my nerd card for it being resolved with a standard update.