Audio routing with external hardware in OBS

Hey gang, I'm trying to record the audio looping through my hardware and back into Ableton then going out of Abletons master chain.
Everything I try seems to capture the pre-hardware loop and the post in the same recording.
I'm using a Lynx Aurora n interface and running through my VT5 and Neve orbit and trying to capture some different mastering moves for my YouTube channel.
I hope this makes sense!
Thanks in advance!

I'm trying to use loopback but it seems to only be able to pick up the pre-master channel if I select Ableton or my audio interface. Everything is routed to 1 + 2 out on Ableton and I have an external input effect inserting the outboard gear into my master channel with some ITB master limiting to finalise it. The final limiting section doesn't seem to be able to be recorded.
I wish I could show you a video as it isn't making sense to me here.