+1 to that.
I'm not looking to make all of those upgrades to a $150 CL bike - just trying to get a sense of what is or isn't eligible for upgrades over time.
everything is eligible for upgrade. You
could take a vintage frame and outfit it with Brand New SRAM or Campy stuff if you wanted to; it would be mucho expensive, but if its what you want it can be done.
In general if you want an easy-to-work-on 80's bike get something of decent Quality from Japan...most of the parts are easier to find and you'll have a lot of options.