Hey there
I am about to start my TR with Travel Service end of the week, so I'll try to answer the question.
I didn't know they work with contractair, but it seems they only call 737TR candidates for the assessment.
They are straight forward and answer very quickly so If you don't get any news from them, it isn't probably good news for you.
the last TR course is scheduled for February , I don't know if there any spot left.
As far as I know, no other selections is scheduled for 2019.