There are some legends around this pedal since it is unbranded, just called The Dirt Box. It's quite obvious that it is a Maxon made pedal and when you check the guts you will see that the pcb copper side states clearly MP-D0701, which means it is an OD-855 Overdrive II. So, everything clarified? No, not at all. Sometimes (on very rare occasions, as this thing is RARE) you can come across a Dirt Box with different guts, namely an OD-850 in disguise (pcb MP-D0501). You cannot tell the difference from the outward - both are just labelled The Dirt Box.
On the edge you will find a kind of a model number, No.15451. So, what's that? Well, it took me a while and meticulous research, but now I am quite sure that this is a Sears Roebuck & Co. catalog number, though by now I couldn't track down a Sears Catalog listing this particular pedal. But there are lots of other musical products with a five digits number, starting by 15xxx in 1970s Sears catalogs.
An intersting fact is, the "Amplifer" misspelling on the left edge, which I could not find on other Dirt Boxes I came across. Thus mine seems to be from a pre-production run and the mishap was then fixed for production.
02/25/2017: ToneHome is looking for an Ibanez CS-505 narrow box first issue with flying fingers side graphic. Any hint is highly appreciated. Other than that we're looking for boxed effects or just boxes for Ibanez narrow box GE-601, AD-80, CP-835, OD-850. Please submit your offers or leads here: e-mail