Picked up a few coins at a local antique fair this morning in Cheshire. I know there are many varieties and hope it has some value.
Pretty sure this is KM# 69 which is undated. (Has the digits 45 in the legend - probably 45th year of Shah Alam II, which would make it around 1838, but probably a frozen date.) No idea on significance of the XX - could be a merchant's chop mark, or worryingly an indication of a modern copy. Same variant and condition sell on Ebay for around £20 but there are sellers asking a lot more.