I collect the 36' reefers made by MTH and I'm trying to collect one of each. Here is a picture of what I have (that will fit on the Glen Snyder shelving that I can currently get my hands on) (The empty spaces are for cars that I am missing):
I still have over 40 cars that I do not have the shelving space for. I contacted Glen Synder and was told their O-gauge shelving wouldn't be back in stock until at least June of this year.
I also have 46 cars on pre-order, which most (if not all) are coming in this month! It's going to be an expensive month for me!