It's certainly worth asking. I've lent my powerboat trailer to several people I've never met over the last few years, and takes a certain risk, but I tend to trust those forumites who have been around for a little while
Lots of these trailers in Perth but then that is 20000 miles away. Around here possibly 1 in 2 owners of fin keel yachts in this size have a trailer for it sorry that is no help at all except you might like to build/buy one they are a good thing to have. will
Machurley 22 I can't imagine a motor boat trailer being any use for a fin keel boat. A typical trailer will have a U channel steel centre member becoming the draw bar into which the keel sits. On each side members come up at an angle to the gunwhale level with padded supports to keep it upright. the axles and wheels are mounted at the side support members. All the boat weight is on the keel however if you have doubts about the strength iof the hull then cross member supports in front of the keel and a removable support aft of the keel can be jacked up to take some of the weight. The boat is floated on to the trailer which has been run into the water deep enough to float the boat on. This is usually done on the end of a rope, you need a jockey wheel at the front for it to run on.
One variation on a jinker here uses cross members only with the keel dangling unsupported in this case the boat is floated on sideways.
With trailers there is always the problem of brakes and bearings needing a lot of service but this is doable. Lights are usually detatchable. Around here cranes for boat lifting are expensive and unusual as large boats stay in the water all the time except for hauling out for a few days on a slip or boat lifter. many people with boats your size will take them home on a trailer each winter for maintenance but it is a totally do it yourself process with help from crew. give it a try will