Type 502 Manual (weight and colour)

Roy Thistle

Hi All:
How much does a Type 502 Manual weigh... approximately... I'm guessing 1.5 pounds?
Also... I see some of them that are a dark green... and others that are the Tek blue... with a cutout on the front? ("showing 502")... and bound with those white plastic combs.
I thing the green ones a much older... are the blue ones legit... or photocopied and bound fakes?
Best regards and wishes.