Water stain on crewel work that is 31 years old

by Pam

I recently purchased online, a crewel piece, that had been framed for a number of years.

This piece was dry cleaned hoping the ? water stains would come out. They didn't.

Before I try any thing else I thought someone here might have a suggestion. If not, I will just leave as is and tell the recipient about it.

Thank you for any help you might give,

Pam