Cool find.
That's a lot of maintenance, but the mileage intervals they give suggest some people did what would be a fairly average amount of driving these days. 300 miles a week is a little less than 16K a year. It would be over 100K by 7 years...if one of these cars lasted that long in regular use.
In a funny way it's kind of simple...everything either takes "motor oil" or "cup grease." Not to mention the amounts..."few drops," "thoroughly."