Posting Apparent Altered 508 To Appear As 508c For Opinions & Discussion...

As I recall, this example is from the wrong position on the sheet to have the error.

Found the Armstrong reference... thanks.

Hi disi123,
Could you provide a link to the reference you mention please?

The 'reference' is pg 94 from the Armstrong book depicted above...

I assume the reference is
Martin A. Armstrong

Washington Franklin 1908-21

It is. He wrote two other books, one on the early coils and one on the fourth bureau issues of 1922-1938.

Balderdash!

The explanation in Armstrong's book is incoherent at best. It may rank among one of the top 10 reasons the books are not as highly regarded as some may believe. The definitive article about the subject was published in the United States Specialist some years ago. I don't have the reference handy, but this short explanation by Larry Weiss in 2008 should be helpful:

To me the important point was that the error is in the third row of perfs, making this example a clear fake.

Thanks for the reference. Looked it up on Amazon, and it's out of stock. However, did find quite a few useful guides on StampSmarter.

Txphl - You can find the reference publications here:

https://www.philbansner.com/philate...-results.htm

Thank you, @rogdcam.

Since I've started participating on this board, instead of just passively reading, my bookmarks runneth over.

This begs a few questions...

Where did the Specialist obtain the data?

Where did Weiss obtain the data?

Last, assumedly both of the above were many years subsequent to
Armstrong, why wouldn't the identical data be found in his book,
as opposed to the data on pg94?

I am not sure there is a data source. The article provides a detailed description of pin layout from the beginning to the end of the perf 10 section, about the width of two stamps. From the description does not support Armstrong's description, whatever he was trying to say. It is also likely that Larry Weiss' explanation, hastily posted yesterday, is also incorrect. The article notes that the perf-10 row of pins is misaligned relative to the perf-11 row around the cylinder. The perf 10 row is somewhat irregular, gauging between 10-81 and 10-82 with irregular pin placement. Conventional flat plate perf 10-79 spacing is found on many fakes. If part of an old perf 10 perforating wheel had inserted, why is the pin spacing irregular? We may not have an explanation other than what can be observed by examining genuine examples.