The coins that were struck (they were not minted from scratch) are of varying quality because the impression was made over the top of Roman coins and sometimes parts of the underlying image can be seen. Issues were struck in silver and bronze, and all coins were over-struck on contemporary circulating coinage, most often Roman Provincial issues and Roman Imperial silver denarii. They were obviously intended to replace Roman coins and we can assume that at some point it was no longer possible to “buy or sell” in Judea without Kochba coins as that would have been regarded as “traitorous” to the cause. It was obviously an “in your face” political statement directed at Rome. That coinage bearing the image of the emperor was a problem can be seen from the challenge issued to Christ (Matt.22.16-22). Some of the coins are undated, others are dated to the first, second, third and fourth year of the revolt.
A typical description for a coin of the type portrayed below might be: “Hebrew inscription Jerusalem, tetrastyle facade of the Temple of Jerusalem with Ark of Covenant visible within and star above. [Dated: first year, etc, or undated etc, weight, type etc, inscription etc]” (see diagram below). Of course, the “Ark of the Covenant” was not present in Herod’s temple so is this an anachronism? Leen Ritmeyer suggests that it depicts the portico of the temple and he bases his architectural reconstruction on the coin (see diagram below).
In my “abstract” I refer to the star elevated above the “Ark of the Covenant” but further consideration leads me to the conclusion that the coin depicts the “Torah Ark”. The Torah ark (or Holy Ark) is generally a receptacle, or ornamental closet, which contains each synagogue's Torah scrolls (see diagram below). This better “fits” the context of the time period with the “Ark of the Covenant” now replaced by the “Torah Ark” especially as Kochba regarded himself as the “Torah made flesh” (see previous post). In other words, the Law has replaced the Ark of the Covenant and Bar Kochba is now the personification of the Law – he is the “prince of Israel” (as stated on his coins) and the messiah (as declared by the chief Rabbi). Our argument would be that Kochba initially pitched a tent that contained a “Torah Ark” and built a temporary sacrificial altar in anticipation of restoring and building a “Third Temple” to herald the messianic age.
 Some scholars have the revolt lasting 2.5 years, however we argue for 3.5 years: obviously there is something going on with the “dating system” (don’t forget we have a civil and religious New Year) – this could explain “year four” coins; See Chapter 8 page 141. https://www.biblaridion.info/html/ch8.html
 Wildwinds is a website that has Ancient Coinage of Judaea for auction. http://www.wildwinds.com/coins/greece/judaea/t.html