I have heard people asking about what were the appropriate parts for a bike from the 1970's. Here is what happened to many, many 1970's low and midrange bikes with steel cranks and simplex gears. They got Japanified. In fact, this bike struck a chord with me because I had the next model down (it's a 1972 or 1971), and I upgraded to the same crankset (Sugino Maxy) and same rear mech (Suntour VGT).
A bike like this is reasonably light (26 or 27 lbs) for a low-end bike and the brakes and gears work very well. It would provide years of reliable service and be easy to tune.
- Don Gillies
San Diego, CA