My first assumption would have been motorcycle. Small wrenches for this and that on the bike; large box wrench for the nuts tightening the rear axle. Looks very similar to the kits that came with the Yamahahaha* motorcyles that friends had back when I was young**.
*In those days, the "serious" riders all rode English motorcycles, BMWs, or Harleys, with the occasional (real) Indian thrown in. That was before the Japanese makers started making big motorcycles.
**Some mornings, it's hard to believe I ever was, although I think I'm as childish now as then.