As a part of my ongoing education, I would appreciate knowing the forum members' opinions about the 1829 ruble has just been sold on eBay for $177.50 (not sure how to add the link, hope you can find it).
I did not bid - I would have no idea what that thing is because the image of one side is completely out of focus. I guess I would have no idea even if I could see it, but that is just me.

http://cgi.ebay.com/1829-RUSSIAN-SILVER-RO...emZ330230891618

Good price for this coin.

You wouldn't be able to find it going any lower unless it's holed or damaged in one way or the other. That's the prices these days.

Check the picture of my coin, my avatar, an 1826 Rouble of the same type. There are several differences in the dies used. According to various experts, the hubs for these coins were created from "piece part" punches. Look at the 1826 and compare to this 1829. It's very interesting to see the obverse differences. I don't think the 1829 is counterfeit, however. I know they tinkered with the eagle. In 1830, they made some very significant changes to the eagle and the ribbon. The eagle's wings, on my coin, don't touch the rims; on the 1829, they do. There are other differences. For instance, the shape of the "O"s in Moneta and Goda. See if you can spot them.

Many thanks for the input. Btw, I found very nice images of both types on the site:

http://www.ngsa.ch/en/ench-cat.php?cat=215

that also shows other high quality coins from some past auction.

I have searched for 1829 images on the web and found quite a few. It's been amazing to see that even on the coins of the same year there are some noticeable differences (of course, assuming these coins being authentic). So, here is a small gallery from various web sources that shows a progressively smaller distance (going from left to right) between the right wing tip and the coin rim. The larger distance is actually just like on the marv's 1826 coin.

Click to view attachment

That just goes to show how hand-made these dies were; they were not made from a single master hub, but, according to Julian and others, were created by individual punches for the separate elements of the design.

For example, look at the central spike at the top of the shield. On your middle coin, it clearly extends into the bottom of the crown. On the other examples, it does not. Steve Moulding, in the RNS Journal, did an analysis of die life for this period. I can't remember the results, but, for 1829, there were enough coins made that I'm sure many different dies were used, each of them being created by individual punches. There may have been several punches for the same elements also, so that not only the placement, but the designs could be slightly different for each die.

Once coin dies were produced from master hubs containing the entire design, save the date, these types of small differences were gone.