is it common for 60's schwinns to have original bearings?

[bairdco]

I'm sure many of us have pulled apart hubs, headsets, etc, from 50+ year old bikes that still had the original grease in them, solidified into a greenish black crust.

 

[rustjunkie]

I suppose you could never know for certain if the bearings themselves are original or not. The original bearing retainer can be emptied and refilled with new bearings at any time. Yes, unlikely in most cases but still, I'm sure most of us have done it at some point servicing a bike were getting back on the road.

Schwinn shops stocked the original bearings retainers. These were used when servicing and were sold to customers. It doesn't mean the bearing cage in the bike is original just because it's marked the same as the original.

The literature and packaging I've seen describes ball bearings used in bicycles as "tool steel", "Grade A". I'm guessing that means carbon steel, and while I've not found any precision specs for "grade A" I'm betting it's lower than grade 25 which is what most (good) bicycle shops use today. You get more precision in sphericity, lot variation, and roughness as you move up in grade.
Some shops offer a choice between carbon and chrome steel ball bearings, but many stock only the "better" chrome steel.