I've made several buildings out of DPM modulars, Walters modulars, and Pikestuff wall panels, which I count as scratchbuilding light. I've modified plenty of buildings (usually blanking out windows). But I've never gone whole hogand actually kitbashed something. Impulse bought a classic yesterday and I'm well on my way to making it into something vaguely B&O looking.
The other side has a roll-up door on the first floor. My goal is to be done with it by the end of my three day weekend. Its a hybrid of several B&O towers in the Pittsburgh area. The only one with a brick/block first story was VO in Butler and it had a big roll-up door in the first floor.