Parallel Sides For Imperf Coils And Vending/Affixing Coils

I've recently gotten into the niches of flat plate imperf coils and the confusing world of vending and affixing coils. For the latter, I know there are multiple nuance ways to determine authenticity, but one big glaring question pertaining to both imperf coils and the privately perfed coils is the parallel straight sides. When determining authenticity for Washington Franklin coils, a near perfect or perfect parallel symmetry for the straight edges is a major step in determining whether it is a fake or an authentic coil. I had assumed the same would be true of these...however, there are NUMEROUS examples of imperf and vending/affixing coils being sold that are not even close to parallel--although the majority (but not all) of those with certs do seem to be parallel.

My question is does how much does the straight edge symmetry matter to authenticating either flat plate imperf coils OR vending/affixing coils? And if not, anyone know why it doesn't matter?

Below I've included examples I pulled from online. The first 4 are from the Brody collection sold by Shreves Philatelic Galleries in 2002. Some of the dollar amounts with these runs into thousands, so I assume authenticity was not in question, but the ones below did not come with reported certs.

The last 3 examples are pulled from current offers on ebay. The last one has a PF Cert (but from 1974...if that makes a difference).

If these were perf12 flat plate coils, I would assume all of them were fake.

Bureau produced imperf coils were either hand assembled or auto wound. Hand assembled coils will have parallel edges, that frequently display "hesitation" marks. I have posted on this topic in the past. Auto-wound (single line watermark) coils will have parallel edges similar to early rotary press coils. A few early examples may have been produced before an eleventh knife was added to trim the half sheet (straight edge cut) edges.

Most private vending machine coils were stripped but some may have been cut by hand. Check Steven Belasco's book for more information. Badly cut edges, not consistent with known examples may have fake perforations.

Just like with the bureau perforated coils, there's plenty of fraudulent private perforated and bureau imperforated coil in the market. Use caution just as you would for the perforated coils. Before the bureau started issuing imperforated coils, the vending/affixing machine companies made their own coils from imperforated sheet stamps of 400. Two books you may want to consider for your reference: The Stamp Machines and Coiled Stamps by George P. Howard and Guide to United States Vending and Affixing Machine Perforations 1907-1927 by Steven R. Belasco. If your a member of the USSS, there is a lot of information in their United States Specialist (Journal) data base that you may want to research too. Be careful about buying until you research it a bit.

There are actually 2 types of vending and affixing machine stamps. Those that were actually produced and coiled for usage in the company's machines and those that were made as "request items", produced solely for stamp collectors and dealers.

Each company had their own process for this. Sometimes these were not coiled, but supplied to dealers in sheet form. The dealer would then separate the sheets into blocks, strips or pairs to meet his demand. I would imagine that they were separated with scissors.