Well, Chris it would appear you have an unmamed official Nintendo DKJR Modification Kit! Awesome!
http://mamedev.org/source/src/mame/drivers/dkong.c*****************
Donkey Kong Junior Notes
========================
DJR-03 Donkey Kong Modification Kits 02-23-83
--------------------------------------------------------------
Nintendo Service Department Bulletin # DJR-03 02-23-83
GAME: Donkey Kong Junior
SUBJECT: Play Time
It has come to our attention that play time on Donkey Kong
Junior is, in some cases, excessive, while in other cases
there is concern over the ability of players to learn the
game and thereby retain an interest in playing.
We are making available, through our Nintendo Distributors,
two EPROM change kits, designated DJR1-E and DJR1-P.
The E kit consists of four (4) chips and is an easier version
of the program. it presents the board sequence in a way which
familiarizes the players with the game faster. The board
order is vines, springboard, Mario's hideout and keys.
The P kit is a more difficult version consisting of two chips.
The order remains the same while more and faster
obstacles (snapjaws, nitpickers, etc.) are presented. --------------------------------------------------------------
E-Kit - roms
------------------------------------------------
Filename Label Type Loc/PCB CSum
----------- -------------- ------ ------- ---- --
2732.5Ae DJR1-C-5A e 2732 5A(CPU) 68E9
2764.5Be DJR1-C-5B e 2764 5B(CPU) B0CF
2764.5Ce DJR1-C-5C e 2764 5C(CPU) FC64
2764.5Ee DJR1-C-5E e 2764 5E(CPU) 7CC6
------------------------------------------------
P-Kit roms (Still looking for these, suffix is
more than likely P. ![Smiley :)](https://donkeykongforum.net/Smileys/default/smiley.gif)
------------------------------------------------
Filename Label Type Loc/PCB CSum
----------- -------------- ------ ------- ---- --
empty --------- ---- 5A(CPU) ----
2764.5Bp DJR1-C-5B p 2764 5B(CPU) 1B58
2764.5Cp DJR1-C-5C p 2764 5C(CPU) F4FE ------------------------------------------------
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