Guide Dot Or Variety..?

H guys...

Sent this oddity off to BNAPS "dots and scratches" to see what Mike thinks..In the mean time any replies would be appreciated.

Here is my block of Scott 106's.

Now this block is precanceled and inverted cancel, but look at the HUGE dot in with the precancel Scott 106-7-I (TL/P6)
Not sure if it is just a form of guide dot or in face a variety...?

Robert

That to me does not look like a guide dot in the regular way. It looks like a dot on the precancel mat.

Peter

Thats what I was thinking to Peter..Hope some one comes across with the same variety.

Robert

I have usually seen these referred to as "nail heads", which is likely what they are.

John, can you elaborate on that one?

Peter

Although I don't know the specifics in this particular case, often times with standard printing block manufacture, the thin plate of cast metal type is nailed onto a wooden backing block. The nails can slowly come loose to the point where they "take ink" and print.

John

That is a reasonable conclusion..Good one.

Robert

Thank you John. That is a totally different method of overprinting the stamps than we do here in the US!

Peter

Peter, Have you actually seen a local precancel device of any sort? Please explain your view of the US method.

Here is visual evidence why I believe the dot in Wert's example is a nail head: a 2x5 handstamp precancel device showing 3 views. Note the curved metal plate held to the wood base with metal fasteners of some sort.







Lastly, two impressions from devices where the mounting nails/rivets show:



It is fairly easy to find examples of local US precancels showing extraneous circular marks in places on the plate which would be logical attachment points to the backing. And of course the 100-subject double line electro plates are flat rather than curved, but still consist of a thin metal plate mounted to a block of wood.

John, I think we are talking about two different things. I was thinking more of the Bureau precancels, not of the local ones. The plates used on the Transportation Coils were mounted around drum and used screws to hold them down. My mistake.

Peter