Possible Shell rot

[Mason181]

Hello, Ive noticed a discolouration on between the scutes on my 8 year old Marginated Tortoises. Im concerned that this might be Shell rot. Ive included some pictures of his plastron as that is generally recomened to be shown when trying to determine if it is shell rot.

Apologies for the dirt it was cleaned off after.

 

[wellington]

Shell rot usually happens on the plastron not the carapace.
I see nothing of any concern to me.

 

[ZEROPILOT]

I also don't see a fungal issue and certainly not shell rot