*bump*
All the coins are real.
A series of activation, toggle, and de-activation commands MS used in the MoFI editor cause the coins in the east room to toggle whenever you step on a new square.
The game doesn't concern the coins you collected from the original existing set of 37, it just makes sure you have 37 after you get the star.
Therefore it doesn't matter if you used a dozen different toggling coins, one toggling coin, or getting all original coins using wall-blinking because the game only considers the end result of your collection.

Not really around much these years.