There are, of course, some recognised Experts for these areas and others associated with them, including members of the AIEP [International Association of Philatelic Experts]. Mikulski was the most important of these, but he no longer signs because he has sold his Reference collections.
But it's really the BPP which matters. It's the best organised and the most systematically rigorous and reliable, with clear and public rules which you can find in the back of a Michel catalogue. In comparison, some other national organisations which claim to offer expertising services are simply not reliable or reliable only for a few areas. Some of these organisations have been prone to laxness or scandals.
Collectors in the areas in which I specialise should be pleading with the BPP to look for potential Experts and train them for the task. In the case of Ukraine, Dr Seichter, John Bulat and before him Kobylanski were all BPP accredited. Now there is no one. I don't think there has ever been anyone for Transcaucasia. There have been BPP Experts for Poland ( for example, Jungjohann), Russia and Soviet Union (in these cases, not always good choices) but now there are none. Now that Heimbüchler has reached the BPP retirement age, the same is true for Romania.
It does make life difficult for both collectors and dealers. Let me use the example of Ukraine. Here are some stamps I want to sell: a block of 4 mint 10/7 kopeck stamps with an overprint which is "obviously" Podillia and two used 10/7 stamps with overprints which I think are the same. I have put the mint stamps close to the used stamps, but they are not attached to the Money Transfer fragment: