His shop, a refinished basement adorned with cosmic photographs and pottery as well as several lively and colorful parrots, seems to be the type of quirky, esoteric store that many lament is quickly disappearing from Harvard Square.
A large clientele is not materializing for Johnson and many other businesses in Inman Square.
"You have your traditional following at S&S, but elsewhere..." Johnson muses. "There's even a Korean restaurant down the street that installed venetian blinds recently, probably so people who pass can't see that it's empty inside."
Without advertising, Johnson relies primarily on curious local passers-by for business, but cannot afford to make Mud Man the sole source of support for his family.
But as the newer, glitzier operations begin to dominate the square's economy, many residents and business owners say they are bringing in a different breed of customer.
With its large advertising budget and its national reputation, the East Coast Grill in Inman Square, like S&S, continues to thrive.
But that restaurant makes most of its profits from a more transient clientele: tourists. It lacks a strong showing of local regulars.
A restaurant employee says that many of the locals traditionally favor certain spots. But because of an absence of interaction and sense of community among the races in this multicultural region, few locals are willing to try out the newer places.
Many local residents also say that East Cambridge seems to be divided into ethnic zones that rarely mix.
"Each group does its own thing, has its own parades. It seems like a new group, Haitian or Portuguese, is having its parades and such, but they don't tell anybody about it," says a square resident.
Johnson says he has found that some parts of Cambridge surrounding Inman Square are populated almost entirely by a single ethnic group.
And in the middle of all this is a local election. Walsh is running for a fourth term on the Cambridge city council.
The Local Politician
Walsh's re-election posters line many side streets in East Cambridge, hanging even in the storefront windows of failed and abandoned businesses.
Financial successes and woes seem to have divided many Inman Square shopkeepers into ardent Walsh supporters and vehement opponents.