searching for the variable names that make up the red text on the screen (ticket requested, price, cash offered etc)

Hi, did you manage to figure this out? I would be interested in knowing how to do this if so

Im not sure, but there is an app called IBIS Control for OMSI 2 that uses this information through the plugin interface. I ha a quick look in the included *opl file and there I found GivenTicket and ticketprinter_display for example. I hope that was a little help.