Popeye/DK/Mario Bros. --> Jamma adapter ?

[CraftyMech]

I picked up a Popeye pcb several months ago and just got around to building a jamma adapter for it. I didn't realize at the time that the video is inverted, and the audio is un-amplified. Looking around online, it looks like Clay Cowgill used to make an adapter with a 2W amp and adjustable RGB levels, but has stopped making them.

Is there another source that anyone knows of, and if not would anyone be interested in this type of adapter? I could produce a small batch if there was enough interest, otherwise I'll just hack one together and keep it around for testing.

Update: Looks like MikesArcade.com sells one for $45. That is more then I paid for the board itself, so I think I'll hack one together with a simple on-board amp and video inverter circuit.