Would a Tillig NEM TT coupler fit an N gauge NEM Socket

[woodenhead]

https://www.tillig.com/eng/Produkte/produktinfo-08841.html

 

Or is the box bigger?

[D9020 Nimbus]

It would, but it would be bigger than the standard N gauge coupler.

 

These couplings are supplied in "kit" form; you need to put the metallic hook inside the plastic remainder before inserting in the socket. This is tricky (to me, at least) as it's fairly small and very thin — too thin for any of my tweezers to hold it, including the "sprung-closed" type.