This thread has started me on a research project to determine what will be the structures I have accumulated over the years for my in-construction layout. They will be removed from the totes where they are sleeping to be test fitted, to approximately where they will eventually be. Bases will be removed if necessary to accomplish the desired "low look". I have 21 MTH and Lionel units to test and a K-Line construction backhoe unit to try to fit in the village I plan to model.
Thanks so much for the input of others here on the forum for suggesting such good ideas. I never thought of doing these mods until I found this thread.
For me you hit the nail on the head, removing the bases and making something like using Masonite and such to create a single complete base and sidewalk for a street length allows mixing and matching brands of budlings Lionel, MTH, ORG Ameritown, Korber menards, Atlas, DPM...... so you get the cohesiveness a typical city or small town block has, but with the diversity of constructions so they don't all look a like.
While there are a few outliers that have animations like the MTH McDonalds and car wash 99 percent of all buildings on the layout don't have those limitation, so no real surgery required. Even the MTH A&W stand (and its other versions), look more realistic with the base removed and adding period appropriate tables outside, the molded plastic ones in the base are really not to lifelike.