The buttons "numismatics" and "art" of the site do not work. The others are more or less known. The bulgarization of archaeological findinds is also true. What the bulgarian public media present as "ancient bulgarian" things, are mostly hellenistic and roman.
In Bulgaria happens what with other nations having no written history happens: They take advandage of the lack of written history and they claim whatever they want. Albanians do the same claiming that they are Illyrians. On the other hand, nations that have a written history since antiquity are falling victims of their literacy: Their neighbours do some cherry-picking in the ancient texts and select what fits in their national mythology. For example, the so called "Macedonians" of the F.Y. Rep. of Macedonia discovered one or two instances where south Greeks called the ancient Macedonians "barbarians" and they claim that the latter were not Greeks and, thus, they were the ancestors of the today's population of this Republic. Then the field is open for endless discussions in forums.
I've just checked and the Numismatics and Art buttons work fine. Perhaps u should try again.
The site does not claim that the manipulation of Celtic artifacts in Bulgaria is the only instance of such. In fact, other parts of Bulgarian history were similarly 'rewritten' during the 70's and 80's, particularly the so called 'Proto-Bulgarian' period. This is however a different question and is beyond the scope of the balkancelts site.
Yes, today the "numismatics" button works. Leaving aside the micro-environment of celtic settlements in Bulgaria, we notice the striking difference in the coins quality between Greeks and all the others.
That very much depends on what u mean by quality. Because they reject Greek artistic models does not nessecarily make them lower quality. The Celts in Bulgaria (and in general) simply appear to have found Greek art boring.