Working from home today and I just pulled my macbook pro out to realize that I left the "duckhead" part of my magsafe 2 power supply (85W) sitting on my desk when I left the office last night. I happen to have an old power supply from (I think) a PowerBook G4 (65W adapter) that has a similar design with a detachable "duckhead" piece. But I can see that the two power supplies are definitely not identical.
Is it safe to swap the "duckhead" from the old power supply onto the new magsafe 2, or do I need to head in to the office? The "duckhead" from the old supply seems to fit on the magsafe 2 adapter just fine, I just don't know if it is safe.