At the Sept 2008 gun show in Marlboro MA I bought mil surp 7rd steel 1911 mags for cheaper than cheap (3 for $24 in the wrappers, made in 2008). They work flawlessly in my Colt 1911 that I bought at that same show. I imagine that they will work just fine in my S&W 1911 as well. I use Cobra (Virgil Tripp) and Wilson 47D mags in my S&W 1911.
I'll assume whoever was selling them at the MA show probably also does the NH (and maybe ME) shows as well. No idea who I bought them from.