Denis
This book is no longer available from Colvin's site - we acquired a copy recently from Italy with the intention of digitising it (along with Colvin's other books) but have not yet heard from Tom's estate about permission.
We are rather reluctant to lend it out at present, as it would be very difficult to replace if lost. We might be able to arrange something, however.
Are you sure you would want to put one of Tom colvin's flat, Hong-Kong style sails on your trimaran? Would you not be better off with one of the cambered junk sails such as those designed by Arne Kverneland?
Chris