I have an article that I dug out of the Topps Magazine in 1991 during my research into the cause of the 1990 Topps Frank Thomas NNOF. It details a lot of the production process you are asking about and I will attach a full scan of it in my next post. I don't have my new scanner hooked up so the quality is not great.
Your vault items are mostly or all pre-production items, proofing, as Steve mentioned.
As it mentions in the article I'm attaching, pre-production began at the original Topps facility in Brooklyn. I imagine that after a card design had been decided on, many of the proofs that you have in your possession were made. According to the article, after all 792 cards in the 1991 set were ok'd by staff, film was then sent to Duryea to have plates made. In the first few photos of the article you can see the proofing process. It's important to note that the Topps Magazine article is more promotion than journalism. The article implies that the entire printing process was done at Duryea, but two sources inside the company have confirmed that the actual mass printing of uncut sheets required to fulfill the massive production demands of the late 80's and early 90's was done elsewhere. Additionally, the article states that film was sent to Duryea in order to make printing plates, but a former pressman at Quebecor was quoted elsewhere as saying “The film was sent to us. All we had to do was strip it in.”
Regardless of who ultimately did what task, the article is very helpful in piecing together the puzzle and has some great images. Here is the only pre-production photo that I've been able to find:
"Each of the four pieces of color film (black, blue, red, yellow) are inspected before being developed onto metal printing plates."
My knowledge of the rest of the process only covers the time period from late 1989 to 1991. Some of this information is in the Topps Magazine article and some comes from sources inside Topps whom I have spoken with. Topps contracted out printing of most or all baseball cards to Federated Lithographers-Printers, who were then bought by Quebecor Inc. in '89. Printing took place at a plant in Providence, RI, with three shifts working around the clock. Uncut sheets were shipped to the Topps factory in Duryea where they were cut, assembled into packs and then into cases. Each case was stamped with a six digit serial number that indicated the date and shift when it was shipped out to a vendor. From there it went into the hands of dealers, stores and collectors.
Some blown up photos from the article.
An uncut sheet rolling off the press:
Uncut sheet being pulled for inspection by quality control:
Sample sheet being inspected by QC:
Uncut sheet being fed into a cutting/slitting machine
Cut cards in coded boxes getting ready for packing:
Cards being loaded into a new plastic test wrap called polypropylene:
Boxes hand loaded into cases:
The Topps shipping department:
On your last question, you'll see in photo labeled "5" an uncut sheet being fed into a "slitting" machine for cutting.
Employees at both the Topps factory and the Providence plant were required to sign non-disclosure agreements to protect Topps' trade secrets, the details of the production process and, I assume, card population (Topps may have produced over 10 million of each card in 1990). It was difficult to find information on this subject due to the secretive nature of the business.
Oh and one last bonus photo from the archives (I don't remember the date but someone will most definitely recognize the packaging):
