Before personal computers and Excel existed, at least in my world, I used a typewriter to put the pertinent details of each item of Amercan Flyer S gauge I owned on a page in a small pocket sized, loose leaf binder type of notebook. My idea was that if I later aquired another such item, or another car of the same type, I could file the info in the notebook where it belonged. I kept this up for several years, which wasn't too difficult because my purchases of AF train items were pretty few and far between on my lowly bank accountant's salary.
In the mid-1970s I had the opportunity to purchase one collection of AF S gauge trains that, alone, would triple my collection, and I was allowed to pay it off at $50 a month. At about that time, I also aquired a couple of American Flyer Pocket Checklists put out by Ladd Publications. One list was in numerical order and the other was by item type, and they included some of the basic variations such as color, coupler type, etc. I started using a pencil to mark down in each booklet which ones I had of each type and variation. I would write in the number if I had more than one of an item.
I transferred this information to a new Greenburg price guide after they became available. Every few years, I would buy a new guide and transfer my notes from the previous well worn copy. I would keep a copy in my safe deposit box, which wasn't too difficult because by that time my desk was just a short walk across the main floor of the bank from the main vault.
I became fairly proficient in Excel at work, and I have always intended to move my inventory to that platform. I have been retired for 10 years now, and although my AF collection has doubled since then, not to mention additional items by MTH, American Models, S Helper, Lionel and Marx, I have yet to do so. I have inventoried my extensive library of railroad and toy train books on Excel, though, so I may yet tackle this project, especially since it has been a good long time since I updated my collection in a price guide.
One key piece of information on any such inventory for me will be "location" since my collection is spread out among seven different locations between two homes.
I better get to it before "The Big One" hits here in Oregon.
Cheers!
Alan