1792 Stipple Engraving of Lady Hamilton as Sibyl by G.T. Stubbs - Condition/Value advice?

Hi everyone,
I recently acquired this antique stipple engraving and would love to get your thoughts on it. From my research, it appears to be an original 1790s print depicting Lady Emma Hamilton as a Sibyl, engraved by George Townley Stubbs (London).
It looks like an exact match to the one held in the British Museum collection (Museum number 1888,0716.326).
The publication line at the bottom is fully intact and reads: "London. Pub. by T. Stubbs, No. 57, High Street, Marylebone, April 4th, 1792". It is partially hand-colored (blue turban and yellow accents), and the original plate mark is clearly visible in the paper.
It is currently unframed. As you can see from the photos, it has some condition issues: there is distinct foxing/spotting near the top, some water staining, and wear/minor tearing along the outer margins. The central image and the text line are clean.
I would greatly appreciate any insights on this piece! Does the coloring look contemporary to the period? Given the current foxing and condition, what would be a fair market value for a piece like this in today's market?
Thank you in advance for your help!
Best regards,
Harriet