I have a couple stainless 1911 magazines that came with a 70 series nickel Colt I obtained a couple months ago.  I have tried googling, and haven't found any real information on them other that poor quality in their other magazines.  I really want to sell them but want to ask a reasonable price and don't want to sell them if they are garbage.  What is the consensus on the quality of these in the 1911 (hard to mess up a 1911 magazine but I am sure there is bound to be somebody that can make anything poorly) and what would these be worth?

Have you tried them yet so see if they work in your 1911? Previous owner could have had them since they were the magazine that seemed to work best for whatever reason.

They probably would work, but I have no interest in non-factory magazines for any gun.  All of my detachable magazine rifles and pistols have factory magazines, and I am a "markings" OCD collector/shooter/accumulator.

Bet they'd run in my HiPoints.  

While USA brand is well known for being best reserved for malfunction drills and over all horrible quality I would see if they run as beater mags first.
Keep in mind unless you go back like 40 years all Colt "brand" magazines are actually aftermarket anyway, as Colt subcontracted to companies like check mate and metalform for magazines.
Most everyone in the 1911 community has a favorite magazine that works best for them ( Wilson tripp chip McCormick etc) so getting hung up on only factory mags for a 1911 is unwise

This.  Though, Mec-Gar is factory for some, but they are all I use in my 1911.