In my understanding Nova is a marketing company. In that they have neither the smelting plants or the drawing mills. Reynolds (and Columbus, Tange, True Temper{now gone** and I think Kaisei) are companies that both process/draw the smelter provided bar into tubing and then market, usually through a intermediary, the tubes.

Another way to look at this question is that every bike brand that has "their own" tube set is also only a marketing company. (Excepting the very few who do make their own carbon matts, tow and tube) Andy