Topeka ? Jim Rinner’s scaffold-acquired view of the Statehouse’s interior dome offers a rare, up-close perspective of mural paintings, plaster details and copper embellishments encircling the space.

Grunge obscured all but the boldest features of decorative elements until the network of temporary stairs and platforms brought cleaning crews within reach.

“This copper in the inner dome hasn’t been touched since it was originally put up there,” said Rinner, project manager at JE Dunn Construction. “One hundred years of dirt and grime.”

This round of interior renovation has included repair to the series of large murals and plaster works that have been subjected to water damage. Copper covering iron beams and wrapping segments inside the dome have been transformed from a murky black to shiny tan.

“We do some tinting, highlighting so you can see more of the character of it,” Rinner said. “Then we do a clear varnish on top. That will protect it for years.”

He said autographs left by visitors who climbed circular stairs in the dome will be lost in the restoration. A portion will be retained for the historical record and pictures taken of the remainder, he said.

While the campaign to rehabilitate the dome’s interior proceeds, proposals to spend an extra $21 million to replace copper covering the dome and the House and Senate chambers irritate politicians returning Monday for the 2012 session who wonder when cost escalations will end.

The project started in 2001 was expected to cost taxpayers $120 million. Additions to the plan and obstacles raised the figure to $320 million.

Barry Greis, the Statehouse architect, said the plan had been to repair rather than replace copper roofing. Despite continuous patching during the past 10 years, he said, water continues to seep into the structure.

Estimated cost of replacing copper on the dome is set at $10.3 million, while a new copper roof over the legislative chambers may cost $11.3 million. The state can recoup $250,000 by salvaging old copper roofing, Greis said.

The dome’s steel ribs are in good shape, Rinner said, but the exterior copper was beyond repair.

“The copper is in very bad shape,” the construction manager said.

The goal has been to bring the Statehouse’s physical plant and office space to modern standards and bring other elements of the Capitol to mint condition as it appeared in 1903.

The work is financed by issuing state bonds that must be repaid by taxpayers.