It might help somebody who is dealing with a stuck track rod end.
I ended up using STANLEY FMHT0-74886 250 mm Fatmax Locking Mole Grip Curve Jaw Pliers to lock the inner track rod, and STANLEY Adjustable Demolition Wrench 10" to turn the track rod end (it was fatter than my normal spanner). I pre-soaked everything in penetrating oil for 24h. It took some wrestling and a gentle nudge or two with a hammer, but once it started turning it was easy to remove.