Did you try the cornstarch/alcohol trick?
When I did my conversion on Sanyo 4910, I actually found that if I turned on the fridge for a little while, I could actually feel the heat from the line in the top of the fridge. I marked it off and drilled my hole 2-3" away from where I could feel the heat, just to be safe.
It came out perfect.
That being said, they ARE different models, so proceed with caution and good luck!
Primary: NB's Cream Ale
Bottled: NB's Chocolate Milk Stout