So I messed up and now I'm not sure how to proceed.
I bought an antique Brigg umbrella on Ebay and it arrived today. The condition and everything looked as it did from the listing, so I went ahead and gave positive feedback.
Upon closer inspection, however, it appears to be an umbrella by S. Fox & Co, with a handle stamped Brigg, possibly a replacement at some time in the past.
Have I screwed myself as the buyer by having given positive feedback?