I have written about the effort of Tango Via to digitally archive the entire tango catalogue, and how I was impressed with their ambitions, the work so far and the significance of preserving the tango culture for the future.
This is an update to point your attention to their donation page, you can donate via Help Argentina if you are outside Argentina. If in Argentina, they suggest you get in touch with them to get instructions for donations. If you have important original material, that is also a way to contribute to the project, but I suspect hard cash is what my readers are most likely to have for offer. US residents get a tax exempt under the terms of 501(c.3).