I've never built any boxes from scratch, but I've modified the baffles on home stereo speakers that I had found in 2nd hand stores, but only if the build was solid. In the past, I've had to borrow tools as needed, with limited degrees of success. One tool was called a keyhole saw (hand-held, unpowered), which was convenient for such work, but the cut was pretty rough. What can you guys recommend in place of a keyhole saw for baffle surgery on a pre-made speakerbox? (I usually leave the woofer cutouts alone and modify the mid/high sections.)