Ash ballast almost completely covering the sleepers was the usual thing pre-WW1. I wouldn't exactly call the first photograph 'untidy'. Untidy was far more the late 1950s under BR than the pre-WW1 era. And the second picture was taken on the Easingwold Railway which was a small almost impoverished independent line. They hired tank engines from the LNER after the 1924 Grouping and they were too tall to fit in the line's original engine shed so they were parked outside. Slightly overgrown is the what I'd call the Easingwold's trackwork.
I wouldn't call the trackwork in the painting of York station untidy either, but it's a good example of pre-WW1 ballasting which almost completely covers the sleepers.
As to your question, - no I don't know of anything like WW1 era bullhead procedural track being available for Trainz. For light railway use I've retextured some of Pencil's 60lb flatbottomed track to look more the part, but it's more than likely not what you're looking for. Even with Pencil's track it has to be sunk lower in the ground to get rid of the high shouldered ballast appearance. The only bullhead track that ever looked anything close to pre-WW1 era track was the old TS2004 Uk Bullhead-Wooden track by rumour3 <KUID2:79563:1042:2> which is what I used for a long time on my own layouts.