@pjx2-2,
"WOW, you've gotten into this stuff. Shame on you".
I have been into saving, collecting, rehabbing vintage toys since I was a kid, (a Baby Boomer) when mom would donate or throw out our toys, unless we hid them in the attic, where she would not go. I've learned to use "collecting" books and the computer to find out about toys I'm not familiar with, or that were produced by companies that did not last long. I've got a few old toys that took years to identify, who made them, or to find out how they worked or what accessories they came with. As a result I have amassed a lot of books, saved hundreds of site links, and a lot of useless, to most people, knowledge about vintage/antique toys, and I am still learning.
"I started out with an Erector Set, knowing nothing about it (today) but recalling it/them from years way past and then I bought another set (WHY??) and wanted to find out something about this guy and his "toys".
That's how it can start, then the next thing you know, you start playing with them and buying more of them, which can lead to expanding your interest into other directions, until you're accused of being an addict or hoarder.
"I really wanted to sell this on ebay but I think that I need to describe an item clearly and truthfully in order to make some other dolt want to buy it. At this point, I've spent about 4 days (not including purchase price of 2nd set) and have NO idea what I want to list it for".
Your best bet to find out what A.C. Gilbert Erector sets sell for is to do an advanced search for sold/completed listings. Open the listings to see what is included in them, since many are missing parts, and to compare what you have to the listings that sold. Often you can find info in the listing titles or descriptions that can help you identify sets, parts, motors, etc.. At the top of a results page you can toggle between Buy It Now, and Auction listings to see which would be a better way to list what you have.
"I recall being stumped by lack of material ("We were poor and I only had 3 Lincoln Logs) so I thought maybe I could attract attention of similar '50's kids and peddle a "dream set" with many, many pieces in it".
Most sets used standardized length girders, plates, gears, wheels, etc. Obviously the sets dedicated to making some of the larger items had longer girders. The 10, 1/2 set you have, which was I believe one of the amusement park sets, which made tall park rides, would have longer length girders, and base plates, the smaller beginner sets shorter girders and smaller base plates and fewer parts. If you can get a parts inventory sheet, you can assemble a complete set, from several others, or from individual parts lots which have been and are sold on ebay.
"A quick stroll through the "Society" tells me that folks there are worried about the parts cups being 2" deep or 2 1/16' deep in order to be "original". BTW, all of my parts cups have the same enigmatic "pry up" message inside the bottom of the cup. Where did this cup material come from??? Ahhh, the mystery".
Dedicated collectors will obsess over things like that. The difference between cup depth could be because pre-war set's parts were a thicker gauge metal than post war ones. That info can probably be found on the Heritage site I posted a link to yesterday. If you can date the two sets you can try using a caliper to see if there's a difference in thickness of girders or base plates. There could be variations in the thickness of parts from sets produced in the `50s to those made in the later `60s as interest in the sets was waning and costs had to be brought down. Remember, for a while girders and other items were made of plastic.
I have 4 or 5 erector sets in my storage locker and do not remember any of them having parts cups. One has a cardboard insert that has some elastic holders for parts. My Guess is if the cups are a plastic material it would be made of thin vacuform plastic.
"THERE IS NO SUCH THING AS FOOLPROOF, BECAUSE FOOLS ARE SO DARNED INGENIOUS!" (unknown)
