Crazy Kong 2 on Konami/Stern Boardset

Here's something we've never come across and couldn't find much info online about.  This is an original Stern Scramble style boardset that has been modified to run Crazy Kong 2 on it.  There is small satellite board on the Z-80 socket on the CPU boardset.  This board plays, but the sound is NOT working, there are some odd noises at times, but we weren't able to get full sound of it the board.  There are two empty rom sockets on the sound board, not sure if this is normal.

Boardset is sold as-is, definitely a unique find. See pictures for more details on its condition.