Some possible sources for Windows 7 updates may be by using 3rd party updaters which pull files from optional MS sources, eg. windows update or microsoft catalogue
Generally these are intended for admin use to save time, or to update isolated machines.
As such you could easily collect all the files on 1 PC and deploy on another.
Some let you chose the OS you want files for no matter what OS you are on, and others will list what is available for the current OS.
In no particular order:
WSUS Offline Update
Update Microsoft Windows and Office without an Internet connection
is a windows-based tool to update a Microsoft Windows machine in an isolated environment.
Sledgehammer (formerly Windows Update MiniTool Wrapper Script)
Windows Update MiniTool is a free alternative to the standard Windows Update; it puts you in control of updates by allowing you to search, install, and block Windows updates as you please.
WuMgr (Update Manager for Windows) is a tool to manage updates of Microsoft products on the Windows operating system. It uses the “Windows Update Agent API” to identify as well as download and install missing updates. It allows the user fine control of updates on modern (Windows 10) operating system versions, comparable to what windows 7 and 8.1 offered.
(seems to work on Windows 7)