The chassis spec’ed in DH’s book is a Tweed Princeton chassis: 13.75 x 2.625 x 4.125 (chrome steel or stainless w/ silk screened lettering),from Mojotone, Weber and others. Andy might have a TAN kit chassis available here on the TAN site. You could use a Weber “Maggie” chassis too. All those chassis’ would have the holes already done. The aluminum chassis used in the “Building a Two Stroke” thread here on the TAN site is a Hammond, 13.5 x 2 x 5. The holes had to be drilled and punched (easy with aluminum) and the front and back panels were made separately. Decide on the cabinet specs first and then picking the chassis that fits.