Welcome to the database.
The difference between Topps and OPC cards is where the card was printed. If printed in the USA it is Topps printed in Canada is OPC. For many years the OPC cards have also had things written in French on the back and sometimes on the front.
No foil for cards from sets that usually do have foil is a printing error. For some reason the card missed the foil stamping process. It is not that rare an error and is not worth any more than a normal "errorless" card, except to collectors that seek out error cards.
I collect: Baseball, Football, Hockey, Mostly Vintage pre1980, My Homie teams - Washington/Baltimore Teams Senators (Twins, Rangers), Expos/Nationals, Redskins, Capitals, Bullets/Wizards - HOFers - Non-sport (mostly TV shows and movies).
My Trade List is very much a work in progress
CaptKirk42s Trading Card Blog Curly W Cards Strive For '65 YouTube klandersen42