I have 4 Centurions:
2 red/white LeMans RS, Tange 2, Shimano Light Action, Sugino GP 130 cranks, areo diacompe brake levers.
1 blue LeMans, Suntour Vx, Suntour barcons, non-aero brake levers.
1 red LeMans, Suntour Cyclone, non-aero brake levers.

The latter 2, Suntour equipped, bikes don't have Tange stickers on the downtube. I forget exactly what they read but it's along the lines of: "Made with... Light Tubeset...". Led me to believe they were gaspipe.

They still get me to work 3-5 days a week.

According to a few websites, Suntour Vx and later the Cyclone, were Suntours top of the line derailers. Is this normal to see them on high tensile frames?