Fridge venting

I am starting the curb side build on my 53 FC and part of this is the fridge. The camper was a park model and never had a LP fridge. I am getting ready to build the cabinets and install a RM 2454 dometic which is both LP and 110. My problem is venting for the LP, since it never had a vent I am not sure how to go about building one. The fridge must sit on a pedestal because of the wheel well, I can still do a hole in the floor but it won't be rite under the back of the fridge, more to the center. I was told I could use two vented access doors and cut holes in the skin, one vent at the bottom of the opening and one at the top. The fridge is only 36 inches tall and sits on a 15 inch tall box.

Would anyone have any hints on the best way for me to build this vent that never existed? Has anyone done it? Pictures would be great to see if you have built one. Thank you