While it certainly looks like a SCOW, Tim's measured her at exactly 12 feet which is a little oversize. The Chichester SCOW is 11'5" while the Lymington SCOW is 11'4".
Stored in a boat shed on the Scillies, apparently the boat hasn't been in the water for over 42 years. Tim has brought her back to Fareham and is looking for a new owner to take her over.
There are more details here on the Classic and Vintage Dinghy Association forum , if you fancy a SCOW like classic dinghy get in touch with Tim.