I have two slight issues, with my uc520 and cisco 7900 series handsets

I have lost the cisco 7920 software, firmware updates and config utilities, i tried to purchase support for them and you can no longer get it so ihave no way of downloading the software. cisco answer is upgrade which i do not want to do and this systems works

the second issue is i have dont have the correct software pack for add the cisco 7920 to my uc520 and i have lost my uk voice software pack

please can any one help

Many thanks