Get yourself a vintage car door handle like this. This one came from an MGB (I always happen to have some around, I'm a British sports car enthusiast), but you can find them cheaply on ebay. A few things will need to be done to it before we can attach it to the door. In your case, it will depend on the kind of handle you can find. Notice that there is are two small bolts (one on the right and one on the left, these will hold the handle on to the door. Notice the big mechanism for the button, you will carve the wood on the door to let that move freely and preserve the spring action on the handle.