Thought I would post a followup to this thread.....
Controllers came in, xbox-usb adaptors acquired, and after getting past a "short between my chair and the keyboard" on configuring joypads for use in mame, not a bad deal for $23.00 + shipping.
Note: The joystick and buttons on these are not up to par with what I am accustomed to (Happ Controls) but would be fine for younger kids (for which these were intended).
The buttons have the switch built into the button, not cherry switches or leafs. The joys do have what appears to be a restrictor plate underneath so that they could be adjusted to 4-way and perhaps even 2-way if you so desired. A little clunky for my tastes.
I happened to have some spare Happ buttons and joys leftover from previous projects for myself and friends, a lazy Friday night on my hands, so I went ahead and swapped them out.
There's a single button on either side left/right which I wasn't aware of from the online photo and using a joymap utility I found in a different thread, was able to setup and configure Visual Pinball as well. Works like a champ.
All in all, not a bad deal. Granted, I could have gotten the blank box for $20 but having the prewired XBOX PCB is worth the extra $3. Add on some quick disconnects and wal-la, a nice little single player CP.
Steve