If you tried to post a picture, it's not showing. Useful advice will depend on seeing what you're dealing with.

Oops! That would help, eh?! Thanks!

Greetings!

We have been restoring an 1865 Victorian and would be grateful for advice on how to best repair this area of damage (water, termite?) on the oak sill...Thanks in advance for your ideas!

Regards,

Monica

Me feeling is your going to want to pull that trim to at the very least see what is going on behind it. That does not look good. Looks like water damage plus potential termites.

I agree, I would be more concerned what is under that sill, than repairing what is there, that we can see.

Thank you for your input. Seems like I must explore the damage a bit more.