So here's my 7b plate. So how old is it?
Unfortunately, there is no accurate way in which to do that. With the Timken bearing equipped 10" and 12" lathes up through the early 1950's, you could, from the date engraved on the spindle bearings, safely state a date that the lathe couldn't possibly be older than, and from our having gathered bearing dates from several dozen machines, feel comfortable with saying that the lathe wasn't made more than about a year later than the later of the two bearing dates. But Atlas (or maybe Timken) didn't date the bearings in any of the other machines that they made.
At one time, I feel safe in saying that Atlas had records of when each serial number machine was made, or at least the high serial number for each month. But unfortunately, those records have all been either lost or destroyed. So the best that we can do is to guess at how many machines were made and at when the first and last one was made, and assume that over the production life of each machine, the same number were made each month or year (knowing that this isn't true because, given that the company is still in business, they don't still make the old machines).
So on the shapers, we know about when production started and when it ended. And we know that at least 13691 of them were made as someone has reported having the machine with that serial number. We only have 46 machines currently in the database master copy (and I do need to update the copy in Downloads). So to deal in round numbers, I arbitrarily guessed at 15,000 for the total production. We can be pretty sure that more were made during the War years than before or since. And that the number being sold in the late 1950's was less than the average, since they quit making them. But trying to guess as to how many were actually made each year between late 1937 and late 1959 would be a laborious exercise. So anyway, with all of those caveats (or weasel words), the straight line calculation has your machine being made on 09/11/1955. It was almost certainly made earlier than that but how much earlier it's impossible to say. My guess would be three to five years. If someone were to turn up an original invoice with serial number on one of the machines, that might help with the accuracy of the guesstimate.
