If I recall correctly, the Springfield floorplate release is similar to that of the Mauser. A bullet nose is pushed into the recess at the rear of the floorplate, depressing a button, allowing the floorplate to be slid to the rear, where it is released from the front of the trigger guard, allowing it to drop downward. Brownell's used to offer an easy install button for the Mauser floorplate release. Such a thing might be fabricated for the Springfield. Taking measurements off your rifle should be easy. Envisioning the piece is the trick. Perhaps someone can assist with a photo.