(mouseover tool name for episode range)
Elu was (is) a European manufacturer who was purchased by Black & Decker in the 70s or 80s. Their tools were pretty decent, and B&D continued to market them into the 90s before finally consolidating the line mostly into the DeWalt marque, which B&D also owns.
Frankly, I'm no longer convinced they even were Elu, given the B & D parentage. There's every possibility they were B & D Professional to begin with. Whichever they were, they didn't last much beyond the 1st season with the exception of the 2278 biscuit joiner and the corded drill. And curiously, with the exception of the 2278 and the cordless drill, all of them are available as DeWalts.