Brant, I would
NOT bet against that being a Miami-made ring. Even though the pin location is not the typical Miami location for their sweetheart rings, the cutouts on yours ARE Miami looking. If you ever take the crankset out of the frame, plz measure the two hole diameters and the spacing between for us. It would be very informative. Miami has a huge variety of arms and rings so would not surprise me if it came on the bike.
@hoofhearted @Freqman1 ...I would also like to know how you guys feel about this ring....