Yep, it does exist and it is about as rare as anyting that you can imagine. A true Sente Snakepit has the Outback Jack Snakepit sideart on the sides of the top along with the full wrap steel control panel. My brothers game has nothing to do with Bally whatsoever. Even the copyright screen when fired up says "Sente Technologies" and it has no mention of Bally. This game is what we call a true dedicated Snake Pit. The plastic encased rom card should be from a dedicated cab and it should say "Sente Technologies" when fired up. All of the copyrights on the game art all say "copyright Sente Technologies Inc 1983" or something extremely similar. No mention of Bally anywhere.
Now, when Bally aquired Sente they made some more Snakepits but these cabs had the generic green and gold sideart and they used a drop in square control panel that bolted into the existing control panel on the game. These are basically what amounts to kit Snakepits. I suppose they are still somewhat "dedicated" but not like the true original Sente Snakepits. Ive heard of other original Sente dedicated Snakepits(not the Bally Sente kit version) but Ive yet to come across them. I only know of two verified dedicated ones. One that my brother has and one still in Europe. I suppose there could always be a couple more out there sitting in the back of a ops long forgotten warehouse or in the hands of a collector who doesnt really post on the internet or interact in the arcade collecting hobby but I only know of two for sure. Basically Snakepit anything is very rare, even the so called Bally Sente "kit" versions.
Ken.