I've tried searching the forums for this, but the results were many and inconclusive, so apologies if it's covered elsewhere already.

I am trying to book LHR-GLA-ILY on ba.com to get the through fare and the BA coded flights to Islay.

Need to fly after work on a Friday, overnight at my own expense in GLA and onward to ILY on Saturday morning; something I've done before.

The only post-5pm flight ba.com is offering ex-LHR is the last flight at 2135. ITA Matrix and various online booking sites also have the 2045 service, much preferable for arrival time in GLA, for the same price.

Is there a way to get ba.com to display this flight? Using multi-city tool does not work because you cannot book the GLA-ILY flight as a BA coded flight the next day, so no result is returned just a screen of red text saying not a route they fly.