US R68B Revenue Stamp Rarity

Is this a R68b?

No. There is no R68b. This isn't a "part perf", it's just a corner sheet stamp. Part perfs are the revenue equivalent of a coil stamp. So either both sides or top and bottom need to be perfed. But a side and a top/bottom is just from a corner.

Also, even if it does have parallel imperforate sides, there are numerous factors that need to be considered when determining if it is genuine (size of margins, cancel date, cancel type, ink color and impression, paper color and type), and EVEN THEN, when it comes to the scarce part perfs, you need to get it expertized.

The most insidious fakes of part perfs are not those that are created by trimming perforated stamps, but rather those created by adding perforations to imperforate stamps, which have the correct paper, color, and impression types. Both part perfs and imperfs share the same characteristics of early printings.

revenuecollector, yes agree. Those are all good points. I was just responding to the corner not being a "part perf". Essentially expertizing one of these is similar to expertizing WF coils.

I like the 1868 cancel on the 50c conveyance and the 1870 cancel on the 5c certificate imperfs.

"Those are all good points. I was just responding to the corner not being a "part perf". Essentially expertizing one of these is similar to expertizing WF coils."

Not quite. With coils, it's all about margins, perfs and physical size. Part perfs have several other factors, and large margins do not automatically make one genuine.