The surcharged air mail provisionals of 1923 (Mi #41-45) were issued 1 October to cover supplementary postage for mail carried by the air lines Tallinn-Helsinki and Tallinn-Riga-Koenigsberg. In other words, these issues were used for regular air mail, NOT for the Ice-flights. Remainders of air stamp 1 (Mi #14) were overprinted for this use.

There are many different forgeries of these famous double triangle air mail issues, both false overprints on original stamps and completely forged stamps and overprints. The printing quality is rather poor on originals and forgeries both, and it is often difficult to tell the difference at first glance. The samples I currently show in these galleries are all made by the Simson-Kull organisation. A few general characteristics can be used to distinguish most of these forgeries from the original stamps:

• Original issues have 10 straight lines with even distances and even right edge between "EESTI" and "OHU", while the lines on forgeries have uneven distances and uneven right edge.
• Original issues have 10 straight lines to the right of "EESTI", but only 9 lines to the left. Most (but not all!) forgeries have 10 lines on both sides.
• Some of the forgeries miss the circular ornament over right shading lines. These are the easiest ones to spot, even in internet auctions with the smallest pictures...