We're all for originality, but a slightly larger rearview mirror makes a nice difference, especially if you have no wing mirrors or frequently use your car with a top (the bottom/back of the top tends to limit your rearward view-this mirror helps). This mirror is slightly larger than the original.
The mirrored surface is also better quality than what we have found on the smaller reproduction Sprite mirrors. Those tend to suffer from increased distortion issues. You'll find better distortion-free optics with this product.
This is the mirror I use on my personal Bugeye Gumby, with no wing mirrors, and it affords enough extra visibility so that just one mirror is enough. This mirror base plate is the same as the stock original so you can easily remove the two phillips head machine screws from the dash and screw this one into the very same two holes without modifying your dash.
This is a highly recommended upgrade and while not technically correct it still looks right and will help improve your visibility of your surroundings while driving your Sprite.