Sorry! just come across this only 9 years late replying but if anyone is still interested, I dont have any photos of the levi in question but I know it was raced by an old freind of my fathers. His name was Sid Healy (GrandFather of the rugby player Austin) the boat was called Stingray and was actually on course to win its class until very late in the race when it suffered engine failure.
You might find a drawing of it in From Dhows to Delta by Sonny Levi
There might be a picture of it in Bill Shakespears old book
If you send me your email I can send you a picture of my
Levi 17 racing in 79 !
Guernsey - The home of offshore powerboat racing