With no help so far from the internet, I’m looking to recondition the drivers of a pair of Sanusi SP-5500X loudspeakers. These include one 12” and two 4” paper cones that have, over their 34 years of life, have become quite aged…dried and dusty. I’m not looking to have these replaced just yet, just investigating if there is a fix available to get them “rehydrated”. I don’t consider the drivers to be brittle or on the verge of collapsing, but they do need some basic first aid and I’m thinking there may be a product available where it can be either spayed or lightly brushed on that will reconstitute the pulp material. Thanks.

Are the surrounds viable? Are they rubber or foam?

MarkS...the surrounds are foam and in good condition. The driver cones are intact but extremely dry due their age. When I get to my laptop after work I'll add a recent pic.

Here's that shot of the SP-5500X