For Keith Chilcote, the best pieces come with a bit of mystery.

Equal parts art and utility, Keith and his wife, Sarah, have amassed a sizeable collection of Victorian-era hardware and fixtures as part of their home-based business, American Antique Hardware.

The Chilcotes' interest in antique hardware began in earnest with the purchase of their home, which was constructed in 1893. After moving to Salem in 1991 they found out about the house, which was in danger of being razed, and had it moved to its current site.

While the shell of the house was intact, much of the interior had been renovated for use as a six-unit apartment complex.

"As we started digging into the walls we would find tracks for pocket doors and that would put us on the lookout for antique doors and the hardware to go with them. We started trying to restore it to its original glory," Keith said.

The online auction house eBay proved to be a huge resource for tracking the items they wanted or people who knew where they might find the objects of their desire.

"Antique hardware is typically sold in lots of similar items, but we didn't have a use for all of them," Keith said. "We began reselling what we didn't use to recoup the initial cost."

When they decided to start a new family through adoption, they set up a Web site, americanantiquehardware.com, so that Sarah could work from home. It has become a cottage industry.

The thrill, however, is in pieces that can't be identified on sight.

After pulling out one such piece - a doorknob - Keith begins talking through it as though he were the only one in the room.

"I still think it might have something to do with the KKK," he said, almost under his breath.

Time and use have eroded the details, but the knob, which Keith believes was created between 1870 and 1890, retains three distinct symbols. In the upper right, a flame with a cross inside - more Red Cross than crucifixion. The Methodist cross within a flame is an approximation, but not an exact match. A globe rests in the bottom of the knob face; upon close inspection it seems to reveal etched latitude lines. The third symbol, in the upper left, is the most puzzling. At first glance, the creature looks like a fire-breathing dragon, but it's more likely a crane with something in its mouth and its wings spread preparing to take flight.

"I found it on eBay," said Keith. "It was in with a lot of other items, but this one was in the back of one of the photos."

He bought the lot specifically for the unknown doorknob five years ago and has yet to uncover its origin.

Sarah catalogs incoming and outgoing pieces, and when she can, documents the provenance of the most unique items, like doorknobs commissioned for a Mason hall or the Grand United Order of Odd Fellows, an African American fraternal organization. She keeps research guides and highlights the items that have passed through their hands.

Keith, a mechanical engineer, repairs broken pieces as they arrive and reunites set pieces or combines them with similar items for sale, but he's developed an artisan pursuit of his own.

"Most of the houses, like ours, predate the common availability of residential electricity and Victorian-era switch plates are rare," Keith said.

He's taken to creating period-inspired switch plates and other reproductions such as door knockers, picture hangers, and novelty items like winestoppers designed to look like Victorian doorbells. He sells the pieces through the Web site and eBay. A fan of hidden spaces, one of Keith's most recent creations is a doorknob that hides its own key.

Most are injection-molded plastic, which has caused some consternation to customers, but it boils down to practicality.

"These aren't items that were mass-produced. The cost of forging the small pieces in small numbers would cost more than we'd ever be able to make back," Keith said.

While the reproduction pieces make fine stand-ins, both Keith and Sarah know that's it's probably only a step for their customers who are likely embarking on a much larger journey.

"When people are get into this [pursuit] what they're looking for is authenticity," Sarah said.