Is my coin this Würzburg coin?

I have the coin below, very worn

It doesn't match any of Würzburgm only this N#162355 

And the Numista catalog doesn't have a diameter, neither Krause neither auction sites that sold it.

My coin is  17.9mm

Can we define this is the size of the coin?

If yes, I will add the information to the catalog

Thank you for any coment

Its not a 1 Kreuzer because they don't have the twigs under the shield but it could also be a 3 Kreuzer coin. They have a similar slightly larger diameter and the same rectangular shield. 

https://www.ma-shops.de/cdma/item.php?id=1063196

But there are also a 6 Kreuzer coin like yours without a square shield from 1808.

https://www.ma-shops.de/koelnermuenzkabinett/item.php?id=30817 (1807 square)

https://www.ma-shops.de/olding/item.php?id=350066 (1808 rectengular)

https://www.ma-shops.de/koelnermuenzkabinett/item.php?id=57541 (1809 rectengular)

You can add a year and your pictures as an example but entering a weight and diameter from a coin in such a low grade is inadvisable (some of the higher grade coins from MA shop have some diameters and weight though).

https://www.ma-shops.de/shops/search.php?searchstr=W%C3%BCrzburg+1+Kreuzer+1808

Thank you very much for your clear explanation master, 

I think you are right, it is the 3 Kreuzer coin 

I am just a bit worried about the difference from 17.9mm to 21mm, seems a lot for a billon coin

btw the weight of my  coin is 1.04g

I will not add as an example because my worn coin would be of no help

Thank you again,

Geison