It seems that there's actually no crazy kong junior game on crazy climber hardware, though there does seem to be one on Moon Cresta hardware. Even falcon's own apparently cloned the real DK Junior board instead of using their crazy climber boards.
It would be an interesting project to see a true crazy kong style remake of DK Junior on the original ck hardware. No background music. New intermission tunes and colors in the style of Crazy Kong. An animated bigsprite for the trapped Donkey Kong. And a part 2 version with a cute attract mode intermission where Crazy Kong taunts Mario, and some interesting changes to make things more difficult. Oh, and it obeys the same 8 normal sprite limit that crazy kong did. Oh, and with correct colors for Junior this time, and a new colorset. 
I'd have to look into Moon Cresta's sprite limitations but I presume it can display more than 8 sprites?
It would be interesting if someone did create a true Crazy Kong JR. It think it'd really have to be someone's passion project though, if it's even a reasonable possibility. Crazy Climber's hardware seems to have a limit of 24K for the program code and Donkey Kong Junior is already 24K. Crazy Kong Part 2 is 24K but Donkey Kong is 16K and the extra 8K was the new code that they had to add in order to replicate the missing sprites with alternate methods - basically replacing sprites with new routines to manually draw things using background tiles instead.
Donkey Kong used all sorts of sprites for even stationary objects like the hammers, prizes, oil drums & fires, conveyor ends, elevators and elevator motors. This is the main reason Crazy Kong is a little janky - the replacement graphics aren't as flexible or easy to implement
Donkey Kong Junior seems to have even more simultaneous on-screen sprites for fruits, keys, moving platforms, moving vines, springboards and of course Kong and his cage parts.. and Junior himself is now two sprites instead of just one.
It'd be cool to see happen but someone would have to be pretty determined to take on a project like this.
