I often see these "Spade Guinea" coins sold for next to nothing, dated from the time of George III. Are they from that actual time, or made later on (1900s)?
They were made in the Victorian period, and probably later as well. They could not have been made during the actual reign of George III because they look close enough to the coins to be considered counterfeits, the penalty for which I believe was death.
they are made of brass and are very light,the reverse legend is never correct for a guinea,often <in memory of the good old days<,there was never an attempt to pass them as real,just used as gambling tokens
No they would never have passed for the real thing, but having the current king's name and portrait on them would imply they are regal, thus the same rule applies.