@Question_Asker There is no need to maintain a mirror of the source code if you would be distributing unchanged binaries. In that case simply pointing the customer to the license and the original source code, in whatever form, by link or in writing, is enough to comply with the license.
Only when modifying the source and producing distributing builds based on those modifications, would you be required to link to your own changes.
In any case, the license never requires you to ship the source code with every rrdistribution of your product. It merely requires you to make the source code available. Providing links to the relevant places complies with that requirement.