These features are avoided where possible, along with features that appear in only some planes of a given type (i.e. Where possible, the flowchart uses parts that were probably replaced less often, such as frogs, depth adjustment screws and lateral adjustment levers.
This approach doesn't guarantee that you'll date your plane correctly, as the flowchart can be thrown off by some hybrids.
The bottom stamp differs by having Niagara Falls, Ontario rather than Bradford, PA on it.
Zippos had a flat bottom until 1946 when the bottoms were indented.
From 1933 to the mid 50s the word Zippo was stamped in block letters. From August, 1949 through July, 2002 Zippos were also produced in Niagara Falls, Canada - the only place other than Bradford, PA where they were ever produced.
The Zippo script logo was developed in the late 40s and was phased-in on the lighter bottom stamp around 1955. About 13.5 million lighters were produced by Zippo Canada.
If your collectible has a patent number then information about its history is recorded.
Send them to me and I'll add them to the flowchart...) If you find errors or discrepancies, Patrick's Plane Type Study is the final authority.The flowchart starts by asking questions about the cast iron bed of your plane.I've chosen the bed as a starting point because it has many easily identifiable markings, and it probably wasn't replaced that often.There are perhaps 10,000 items relating to insulators, fruit jars, medicines, mineral waters, beers, whiskeys, perfumes and hundreds of other items.What Patent Numbers Mean The first Patent Act was signed into effect by George Washington on April 10, 1790.