Due to running out of room on Bradgamer's hard drive with TSC and TSW on it, I removed Trainz 2019 and Trainz a New Era. Stupidly, I didn't just copy over these directories, but reinstalled on to BradsPC. I found that certain routes (such as C&O Hinton Division) from Trainz a New Era did not run well in Trainz 2019.

The outcome is that I will run both on BradsPC.