Originally Posted by skunker

Easiest is to use ITA Matrix (I still much prefer the old version) along with Powertools and then deeplink to an OTA.
EDIT: just re-read your question. I think the problem you're going to run into is searching segment by segment on EF won't give you the availability for the whole direction. Just because R is available for sale on JFK-TYO doesn't mean it will be available for JFK-CGK.

Seems pretty easy to me. This is with inventory turned off:


This is with inventory turned on. Notice the AA code on JL metal isn't available on the outbound: