The Comet Distortion project is a clone of the classic orange BOSS DS-1 Distortion, in continuous production since 1978. It’s got a few things going on in the circuit—the pregain and tone sections are very similar to the Big Muff, while the diode-to-ground hard clipping is similar to circuits like the Distortion+.
The DS-1 had a major circuit revision in 1994 that dropped the original single op-amp in favor of a dual, along with some other changes to accommodate. The original “Made in Japan” version is very well-regarded, while the revised “post-1994” version is not as much. However, it is one of the most frequently-modified pedals out there, with great mods available from Keeley, Analogman and Monte Allums. The circuit itself is a good one—it just suffers from cheap components.
The Comet Distortion will allow you to build either the pre- or post-1994 versions of the circuit, as well as incorporating most of the popular modifications.