Yeah, I did the same in those drawers until I replaced the water heater last spring and moved it to the bottom shelf (Nirvana has no genset). So I used the top shelf for tools and parts by bolting two sets of Dewalt T-Stack drawers through the shelf and (not shown in this pic) adding another set of T-Stacks on top (I got rid of those top four in the pick and put another T-Stack set in there.) They lock together, are removable easily and left me with room on the right side, on top and in back of them for larger stowage like my drill/driver, socket set, etc.
Now we have the front berth drawers for general stowage again. Yay!