When freelance artist Ben Wood and archaeologist Eric Blind heard about a hidden 18th-century mural at Mission Dolores in 2004, they wanted to see it. With permission from the church, they lowered a camera into a 3-by-3-foot trap door in the attic.

“Wow,” was Wood’s first reaction when they saw the digital images of faded abstract patterns and Catholic imagery, including hearts with daggers.

The church projected the images on the dome, and a media storm followed. It was front-page news in the San Francisco Chronicle, postcards were created, and NBC and others picked up the story. Restoration appeared possible.

But today — some 94 years after the mural was first discovered by policeman Charles Fennell as he watched workmen “buttressing the walls of the building” and noticed streaks of color, according to a San Francisco Examiner article from 1918 — the mural is no closer to being restored. Instead, it continues to fade and flake.

Mural paraphernalia is no longer sold at the gift shop. Andrew Galvan, the curator of Mission Dolores, said the cost of restoring the mural outweighs the benefits to the community. Producing the paraphernalia is also a cost the Church can’t afford as people showed no interest to acquire it.

Historians said the issue is the expense and difficulty of moving an 18th-century altarpiece that was set in front of the mural in 1796.

The baroque-style wooden piece with niches for statues arrived from San Blas, Mexico, that year, and historians said it was probably placed in front of the mural at that time.

Wood beams connect the altarpiece to the wall, and separating the two without damaging either would require the surgical precision needed to separate Siamese twins. It would also cost an estimated $2 to $5 million.

“In the current economy, there are other issues more important,” said Galvan, who is a descendant of the native Ohlone people.

Although Galvan called the reredos “a unique piece that can’t be found anywhere else in the United States,” he thinks the church should focus its efforts on helping the community.

According to Sherry P. Parrish, a research associate at UC Berkeley’s Archaeological Research Facility, the mural was probably created by new converts among the Ohlone, “either by direction or inspiration, and was probably produced in the interim before the altar arrived.”

“Both pieces are equally fascinating and intertwined,” said Blind. “It’s an incredibly difficult and costly task to separate them.”

Historians disagree about which is more important, the altarpiece or the mural.

“The painting was believed to be used temporarily until they could afford a nicer altar,” said Tina Foss, vice president of the Missions Foundation.

Wood agreed that the altarpiece is significant, but added, “The mural is an essential part of native history…. [It] is very important because it shows the collaboration of native people and Franciscans.”

In an article for FoundSF, a website that compiles stories, images and videos of San Francisco past and present, Wood wrote that in the late 1980s, Dr. Norman Neuerburg, a noted mission historian, “crawled behind the altar in the cramped space to draw a sketch of the mural.”

Wood heard about Neuerburg’s sketches from Mission Dolores’ previous curator, Guire Cleary, and with the church’s blessing created the first digital images of the mural.

Since then, Wood and Blind have become advocates for its restoration. One option is to restore the mural digitally, but only a 20-by-5-foot stretch of the 32-by-20-foot mural can be photographed; wood beams prohibit access to the lower portion.

Today, the biggest threat to the mural is that most people have forgotten about it, Wood said.

Few experts are hopeful.

“It’s a shame that this rare and unusual piece of cultural California history cannot be saved,” said Parrish.

Donations earmarked for the mural’s restoration can be sent to the Missions Foundation or Mission Dolores.