Can you perform the classic routine where both coins are handed to a spectator and separated into each hand behind their back only to end up with a half dollar and quarter? Would the spectator feel any discrepancies with this modern rendition? Any information is greatly appreciated. Thank you.

You can do it, but it's less fully inspectable than a locking scotch and soda set.

Close to this is David Roth's "The Fugitive Coins" routine. It can be seen in "David Roth's Expert Coin Magic" by Richard Kaufman in Chapter 8 on page 156.

Jim

The routine I learned used a smaller centavo. This meant you could tell the spectator to bring out the big coin first. The magnetic has an english penny which is roughly the same size. I find that if you tell them the coin is smaller, they bring out the half first. Still tho, the magnetic have a certain feel, which is the sense you're asking the spectator to use. Risky, but the focus on smaller could misdirect enough.