It is the specialist tool kit all Stihl technicians would have had and current with the time it was issued.
Contains all the specialist tools to do workshop repairs and rebuilds- all the oil seal inserting tools, flywheel pullers, bearing seating gauges, clutch removal tools etc.
Would have to look into some paperwork in a box to try and narrow down an era- but a very cool kit and worth a small fortune in its day.
You see them on Evil bay on occasion.