QUOTE(gxseries @ Dec 23 2007, 07:15 PM)

It's puzzling - I don't have all the variety works but at first glance it does look quite convincing.
I agree that the style of the obverse die is very close to that of original Ioann roubles. The reverse die definitely does not match those shown in GM for the Anna edge type. However, it is possible that there might be undocumented die combinations. The Anna edge rouble was listed as "Rare" by the Grand Duke in his corpus. With Elizabeth Petrovna's overstriking of Ioann's coins and the various wars and upheavals since that time, the number of surviving examples in private hands has probably shrunk even further. The Anna edge type Ioann rouble was missing from the massive Klingert collection when it was sold in 1910 by Adolph Hess. There was one in "VG" in the 1932 Hess Dubletten sale (not plated, unfortunately).
I am aware of 4 other auction appearances of the Anna edge Ioann III rouble, some of which might (or might not) be duplicate appearances of the same coin. It is possible that there are others that are not known to me - I don't have an exhaustive collection of auction catalogues and there are some significant sales missing from my library. But, if there are others that I don't know about, I do think I'm on safe ground in saying that there are very few examples of the original mintage (about 6,000 coins) which survive in private hands today. I don't know what that number of surviving examples is, but I'm reasonably certain that it is very small.
The reserve price of $2,000 is ridiculously low for such a coin. It is even low for an Ioann rouble of the normal lettered edge type in today's market.
QUOTE(gxseries @ Dec 23 2007, 07:15 PM)

If there are no such die varieties, it can be an unrecorded variety (unlikely - considering the small mintage) or a contemporary overstrike which is quite shocking in my opinion.
A contemporary overstrike is highly unlikely. Overstrikes were generally done for 2 reasons.
The first reason was for revaluation of the coinage, as we see in the various copper overstriking programs in the 1700s.
The second reason was for political purposes such as when there was a desire to remove the image of an earlier Tsar from public view for fear that it would undermine the stability of the throne under the new ruler. Examples are Elizabeth Petrovna's overstriking of Ioann's portrait coinage (and his secret imprisonment in solitary confinement following Elizabeth's coup) and Catherine II overstriking the coins of Peter III after his suspicious and convenient death.
There is no reason for a portrait rouble of Ioann to be overstruck on an earlier coin. It is not impossible for such a coin to exist, perhaps as the result of mint error or the result of some mischievous action by bored mint employees, but it is not likely, in my opinion.
I think serg2222 is probably correct in his suggestion that this is a modern forgery overstruck on a genuine Anna rouble. If it is a fake, it's a dangerous one.