I've heard further from Crispin Holland:

"I have just returned from Hong Kong having emptied Planesong of my father's things.  I have made a web-page about Planesong with some pictures:

http://crisptv.co.uk/Yacht_Planesong_for_sale.html

.. and also here are some technical details:

Registered Tonnage: 13.38

Length 38.50 ft or 11.73m

Breadth 14.30 ft or 4.36m

Depth 5.40 ft or 1.65m"