You need to copy the Trados8.dotm (located originally in C:\Program Files (x86)\SDL International\T2007\TT\Templates) to your Word "startup" folder (C:\Users\<yourprofile>\AppData\Roaming\Microsoft\Word\STARTUP).
Though, full functionality is not guaranteed since no one can guarantee perfect compatibility with 12 years newer Office...

Unknown said:

Probably no solution as the macros used in the old Trados would have to be rewritten to work in the later versions of office

Not true really... I have just checked it and everything seems to be working just great in Word 2016.
The only thing needed is to manually copy the Trados8.dotm template file into the STARTUP folder as I described earlier (create the STARTUP subfolder if needed).

What exactly do you think would need to be rewritten? The Office API is nicely backwards compatible, and Trados macros don't do any magic, so there is no real reason why it would not work in fact.

Of course! Using 64-bit Office is pretty pointless! Even Microsoft strongly suggests in their knowledge base using 32-bit version (unless you have SERIOUSLY good REASON for 64-bit).
https://support.office.com/en-us/article/choose-between-the-64-bit-or-32-bit-version-of-office-2dee7807-8f95-4d0c-b5fe-6c6f49b8d261
https://docs.microsoft.com/en-us/previous-versions/office/office-2013-resource-kit/ee681792%28v=office.15%29