Button of the 29th found on St Lucia in the West Indies

I am currently conducting research regarding the military history of St Lucia in the Windward Islands. Having very recently visited the island, I met a local resident who, over the last forty years has been collecting military artefacts found on the island. Among her collection, most of which have been brought to her by locals who have dug things up accidently and knowing of her interest have brought them to her, there were three of what I believe to be late 18c or early 19c British military buttons. These are of the 5th, 29th and 91st Foot.
The 5th were involved in the capture of the island from the French in 1778 and this is an action that I am currently investigating in detail.
The 91st (then the Shropshire Volunteers) garrisoned the island for a short period prior to being disbanded in 1795, I guess having been ravaged by Yellow Fever.
Currently I am not able to explain the presence is the 29th on the island.
Can anyone enlighten me?
I also have a jpeg of the button if anyone would like to see it please email me.
Thank you
The 5th were involved in the capture of the island from the French in 1778 and this is an action that I am currently investigating in detail.
The 91st (then the Shropshire Volunteers) garrisoned the island for a short period prior to being disbanded in 1795, I guess having been ravaged by Yellow Fever.
Currently I am not able to explain the presence is the 29th on the island.
Can anyone enlighten me?
I also have a jpeg of the button if anyone would like to see it please email me.
Thank you