Old binaries for Telegram for Desktop (TDesktop for short)
Files in TDesktop v* are binaries copied from an existing install.
You should be able to copy them directly over an existing install.
There are also setup files that will install that version of TDesktop available at telegram-for-desktop.en.uptodown.com/windows/old, rather get those if you can. As the size of this repo is already almost a gigabyte I won't mirror them here.
You can also get setups directly from Telegram:
updates.tdesktop.com/tsetup/tsetup.0.9.18.exe