The first reports on the four-alarm fire that gutted the top floor of the old factory in North Philadelphia one night in early April were puzzling.

One called it an "abandoned warehouse." Another speculated it might house a "commercial refrigeration business" on the ground floor.

From the outside the clues - especially in the dark - weren't much help: Across its brow facing Fifth Street, a vintage sign read, "Planet Jr., Farm and Garden Implements." On its the north face, near the train tracks, it said, "Flexible Flyer Coasters."

It was, in fact, a little bit of all of that. But if you had asked almost any local baker or pizza-maker, any deli-man or bistro chef (or set designer or found-art artist, for that matter), they could have told you at once: This was Sander Supply, the hidden treasure house of used Hobart mixers, Vulcan ovens, three-unit kitchen sinks, vintage milkshake makers, dough hooks hanging, pizza pans stacked in leaning towers, three funky, gritty, mesmerizing acres of the stuff, piled six floors deep beside the Amtrak tracks where Fifth meets Glenwood.

The soda fountain at Famous 4th Street Deli came from here. (It's just for looks; doesn't actually work.) Peter Gilmore got his first chairs here for Gilmore's in West Chester. Sarcone's, the South Philly bakery, calls if it needs a long-handled, wooden peel to shovel the loaves into its deep brick oven; no one else locally comes to mind anymore.

One day last week, Bob McFetridge, who once owned Cottman First England Pizza, dropped in to pick up oven-charred 10-inch pizza pans: "There's a plethora of gold here," he said. "If this equipment could talk. . . ."

Soon after he left, miraculously, it did, albeit through the mouthpiece of Lew Goettner Jr., Sander's owner, whose own German-immigrant family ran corner bakeries, lastly one in Ambler.

He would explain, in due course, the wooden sled mounted on the wall of his office, above the cluttered desk where a long-haired gray cat lounged.

But perhaps it would make sense, he said, to start in the basement, work our way up.

He grabbed a six-volt hand lantern. The electricity has been off since the fire April 6.

The investigation of its cause was "inconclusive," not unlike the murky identity of the place - windows broken and edged with soot - in those first TV news reports.

Most of the damage was confined to the top floor, the only one (because it had housed the offices of S.L. Allen Co., the original occupant) faced in handsome, but unfortunately combustible, wood.

Restaurants come and restaurants go, like the tides.

At either end of their life cycle - first as midwives, then as pallbearers - stand used-equipment dealers, Sander now one of the oldest (circa 1929), and since moving to this location (in 1976), easily one of the largest.

The fact is that the old stuff - vintage Vulcan stoves, hulking Hobart mixers - is often preferred by chefs for its low-tech indestructibility.

And at half price (as little as $850 for a reconditioned, six-burner commercial stove versus $2,000 for a new one), Sander sees a lot of start-up trade.

London Grill has bought a small pizza oven. Its neighbor, Rembrandt's, is a customer. Le Bus bought used equipment when it emerged from its first location - a bus.

In 1981, a chef came in looking for a stove, stainless steel tables, and a refrigerator.

He said he was starting a new restaurant on the sagging main street of Manayunk.

The guys at Sander rolled their eyes.

It was for the Canal View Inn, as it turned out, and it launched one of the hottest restaurant revivals in the city.

Lew Goettner swung his light beam down the equipment-stacked canyons in the basement.

He was taking calls in his ear bud from his sons, Dan and Jeff, manning the fort upstairs: "A safety pilot? Sure I have them."

This was his "mixer graveyard," he said, the haunt of bulky, robotlike machines. Their dough hooks, paddles and wire whisks hung from rafters.

Some dated back to the 1920s. There was a vanilla-colored Fortuna dough divider, the shape of a snowman; and brooding by itself, an elephantine, four-ton dough mixer from a defunct Einstein Bagel factory on Castor Avenue.

They were reminders that Sander Supply (a conflating of the name of the original owner, Sam Alexander) started out as a bakery supplier.

Back when open-mouthed jelly pumps were needed to fill the jelly doughnuts, and bundt-like kugelhopf was the rage; back before - one by one - the nearby corner bakeries succumbed, first Laidge's, then Schmidt's, then Schenk's, and finally, Fink's.

The stairwells are shaggy with peeling paint, opening onto floors serving the various needs of the trade.

There are metal shelves, steam tables, and pan racks. Refrigeration units nestled under a ceiling dripping with icicle-like stalactites. Stock pots, coffee urns, and molds for Boston brown bread.

There are vintage soda fountains, some procured for studio sets. Artists have bought whisk attachments - 50 at a clip - to make into lamps.

It is on these upper floors that Goettner points out the hints (sawdust vents, for one) of the building's founding purpose - to make Planet Jr. brand farm implements, and by the dawn of the 1900s, a patented steerable sled called the Flexible Flyer.

The sled (or "coaster") employed novel bendable runners and a signature crossbow-like steering piece.

But for its Quaker inventor, Samuel Leeds Allen, it served another role: It gave his farm-tool workers jobs in the summer, and kept things humming at Fifth and Glenwood.

Not a sled was left when Goettner moved Sander Supply in from Fishtown.

The one on his office wall?

It was one of the last built in North Philadelphia in the 1960s.

He got it, used, on eBay.

Contact columnist Rick Nichols at 215-854-2715 or rnichols@phillynews.com. Read his recent work at http://go.philly.com/ricknichols.