Here's another interesting item. It appears to be the 10c Certificate R33b vertical pair. It is odd that it has the partial diagonal perforations partially through it. Understanding that it has some faults (including scuffs), it appears to be a genuine part. perf. pair to me. There is a fold/crease between the stamps as well.
The stamps are not canceled. They are not proofs.
So... as this has a high CV, what else might this be than the R33b pair? Printers waste?