Dyna Model Products in the late 50s and through most of the sixties had a butcher shop that they sold with an interior, and also sold the interior separately. They show up every now and then on eBay… Edit: Oops, those were HO - sorry…[oops]
The walls would be white, by the way, as well as the fixtures. The other wall would have another counter, and you also need a area (behind that door?) where the actual meat-cutting takes place. Shelves on the walls with condiments and related products would also be appropriate… You also need a big scale, and a cash register on one of the counters.
Gary hit most of the items needed. I worked in a butcher shop during my high school days and from what I remember you also need at least one "butcher’s block for cutting meat, a meat saw (actually a large band saw), a rack of assorted tools and near the counter a large roll of butcher’s paper to wrap the meat after weighing. Looks like a fun project.
I think that you need to have some coolers for meat on display. Maybe some open freezers in the middle with various small packaged meats. Then along the walls have some stand up freezers with the glass see through doors displaying larger cuts of meats. Maybe some beef quarters. Then you may see a small counter with some local farm goods. Eggs, cheeses, maybe a fridge with some milk jugs in it. Then of course theres got to be a gum ball machine by the door for the kids. But of all the various goods sold in the butcher shop, obviously meats would be the majority item. Hope my ideas help.
A walk in refrigerator at the back. If this is in a rural area the store could sell just about anything else. I have seen meat shops that also sell cheese. How about a small deli that sells sandwiches. A couple of tables on the inside and maybe some picnic tables outside if it is by a highway. A good stop for travelers.