In vrestore.slk you'll see something like this at the start. It might give you some clues. The file is written and read by the restore.e macro file. e.g. search slick sources for SCREEN (uppercase).
MONITOR_CONFIGS: 404
MONITOR_CONFIG: 209 0 0 1920 1050,-1600 -120 1600 1200
SCREEN: 1920 1080 -1476 -46 1425 1125 0 0 M 0 0 0 0 1225 1103 0
MDISTATE: 1