We’ve disassembled both devices and can start with some loose test fits for spacing. Here’s an arrangement that removes as little plastic as possible. It keeps most of the Dustbuster handle and attaches the work light body to the end. Physically this design would be very long and has a lot of wasted space. Let’s tighten things up.
We want to keep the Dustbuster switch, so we’re not willing to cut any forward than that. We don’t care about the work light switch, so we can cut that off. In fact everything is fair game up until the battery connector which we want to keep. Pushing the battery connector plate all the way up against the Dustbuster switch gives us the most compact layout feasible.
This will work from a component layout perspective, but it will be tricky to precisely cut all the pieces to fit. The industrial design of both devices have a lot of curves for us to deal with. However, they both have some flat surfaces we can try to use to make our work easier.
The Dustbuster has a flat brace just behind the switch. The work light has a flat surface where the battery compartment ends and the swivel LED begins. If we line them up, we should be able to attach the flat surfaces together. There will be more wasted space this way but the reduced fitting headaches should be worth the trade-off.
(Cross-posted to NewScrewdriver.com)