Greetings Gabriella If you have a 3, 4 or 5 cent from this issue you can check the perfs by comparing. The 2 cent 1910 coil is faked by perforating the imperforate 384, there are no sheet stamps that are perfed 8.5. The cut edges should also be parallel. If you want to certificate (paper) this pair, I would strongly recommend Mr. W T Crowe, an expertiser who also is a member here. His curricula vitae was on the web, where I found him, years ago, and is very impressive. Incredibly helpful/knowledgeable. Certificates were 20.00 for this issue, his turnaround is very quick. Best of luck, cheers , mark
edit: I assume you checked and verified single line watermark.
A little background: I am reorganizing my collection, preparing to sell or give away parts that do not interest me as much so that I can focus on the parts that are more interesting to me. Personally I would rather have more stamps that are face different instead of a group of stamps that I have to study with multiple devices to detect the differences.
Some of my Washington-Franklin coils I plan to group into lots for auction with notes for prospective bidders to study the scans for themselves. For example, one lot would include 2 each of unused singles that are probably #410 and #411, but I would rather let them go for a low bid than bother trying to get certs for them.
The line pair here, if I get a cert showing it to be genuine, I would then sell individually for closer to its market value.
I have several other stamps which I am considering having certified. Thanks for the recommendation for Mr. Crowe. It will be at least a few more days before I am ready to send anything to him.