They are NOT MOUNTING TABS. That guy on the phone is full of it. They are called BAYONETS. I use to own an MB1500. Same exact box as the MB1700 but shorter in overall height and not as many drawers. But the drawer slides are exactly the same. They have one rear bayonet and one front bayonet per slide. In addition to that, they each have one very small sheet metal screw on the front of each slide. 1/4" nut driver for removal of the little sheet metal screws. Bottom wide drawer takes different slides.
My point is this: Bayonet mounts are a very common way to mount slides to a toolbox. They are called "Bayonet Mount" slides. If that guy is correct in saying they don't make slides with "mounting tabs" anymore, then that means Accuride doesn't make slides for toolboxes anymore. In that case, Accuride might as well shut their doors because there's not enough business in just making slides for kitchen cabinets.
I think you need to measure your slides real good and then call Accuride back and get a different person on the phone.