I collect classical US stamps, and in addition to buying directly from various dealers, I participate regularly, via the internet, in many of the major auction house sales. No matter where I buy, I rely heavily on the opinions of the expertizing services before making the purchase of any stamp worth more than $500. I want to first and foremost be aware of any faults that may have been mentioned on all earlier certificates, but I also am interested in the grade that may have been assigned by previous examiners. I may agree or disagree with the latter, but it is an expert's opinion, and I have to take that into account when I decide on the value of the stamp.
The problem is that both dealers and auction houses, whether knowingly or unknowingly, may not disclose all previous certificates on the stamp. Considering the volume of stamps that the dealers and auction houses have to deal with, and the time it takes to vet an individual stamp, it is understandable that they can't afford to do it. In addition, only the PF has a searchable database, and although they attempt to link all previous certificates on a stamp, their system relies, at least in part, on submitters making them aware of the existence of earlier certificates.
I have found dozens of undisclosed certificates since I began carefully searching both the PF database and previous auction listings on the StampAuctionNetwork. Recently, I've built my own database of PSE certificates back to 2005, and the discoveries I've made astound me. I'll give just one example below to start the discussion, but the real point that I'd like to make is that we need to somehow pressure all of the grading entities to create searchable databases.
My example is a #28b listed on HipStamp. I rarely buy on HipStamp or eBay
, but I find them sometimes useful just to compare what is available in the market. This #28b caught my eye because it looked very nice for the issue, and it has a PF cert from 2005 and a PSE cert from 1997. The problem is that there is another opinion rendered on a 2014 PSE cert. The seller may not even be aware of the conflicting certificate, but when buying a stamp costing over $4000, the buyer ought to be aware of it.