Yes the 5002 is a great design, but the back is sealed and there is no way to convert it to dipole operation with an open back. I am not trying to implement them with an open baffle of any kind for my projects. Let me know if you are interested in any of them, as I still have some. The RT-62041 also works great down to about ~1.4 kHz or so, if you know how to notch the response in just the right places.
Obviously, this purchase opportunity is closed since I already paid for the order, so now I do have them for sale, but at my own pricing structure. Please see the link in my signature or in the Swap Meet sub-forum if you have any questions. Thank you for your interest!