Where can I get a Windows 8.1 With Bing ISO image from a Lenovo Thinkpad 8 tablet?

Question

Lenovo

I installed Windows 10 Techical Preview on Lenovo Thinkpad 8, but then decided to roll back to Windows 8.1. Unfortunately, I did not make a backup copy of the system (I hope someone has). But it was not so easy to do so. There was Windows 8.1 With Bing and the key to it did not fit the regular edition of Windows 8.1 (Core). Now there is an English-language clean image of Windows 8.1 With Bing (downloaded from torrent), installed drivers downloaded from the Lenovo website. Fortunately, the activation key, just like the license, of the operating system has been preserved. Exact tablet model: Lenovo Thinkpad 8 20BN003SRT .
My question is: where can I get an ISO image of the preinstalled operating system of this tablet, or at least a Russian-language image of Windows 8.1 With Bing (not SL)? Does anyone have a saved image?