Re: Is there a method to make my new shorelander fit my boat
He probably doesn't have keel rollers if it's a wobble trailer. None of mine do.
Chances are if it was set up for a trihull, it's adjusted to a fairly high position with your boat on it. I'd loosen all the wobble roller mounts a bit, make sure the roller arms and axles can move somewhat freely, then put you boat on the trailer. This should let the wobble rollers sort of find their position under the boat. You can then raise or lower the cross members or widen or narrow the roller adjustments to suit your boat.
Shoreland'r made several types of wobble trailers, a pic would help a lot so we can see exactly what you have to deal with.
I just converted one from a V hull adjustment to a trihull, what I found was that I needed to raise all the adjustments all the way to let the boat clear the fenders.