Are you replacing an original sprayhood, in which case do you have the fabric with you (or template)to be able to use for the new canvas? Is this a completely new sprayhood where a S.S. framework will be needed to be shipped out to Nidri.
Otherwise the frame will need to be measured and a template made, say out of polythene sheet. Should you end up looking for someone local in the Levkas area then Nick (Greek) of “Waypoint Rigging” in Preveza +30 6932 447002 is a trustworthy and well respected local supplier/rigger. He is in great demand however and with road strikes etc contributing to supply problems, he can miss deadlines.
Other local suppliers such as Sioux Sails, Gheco Boat covers, can be found with others on http://www.theionian.com