does look similar to a nacra 570

that craig's list matrix has no tramp, and google turns up other matrix 5.5 owners looking for tramps....sure the armish outfit or any decent sail shop could make up a couple of tramps to string together hobie style. with the center lacing they don't even need exact measurements

check your sail for any residual glue from an old matrix logo as on the craig's list boat

google also turned up a link between supercat and a "matrix marine inc" so might be worth a question on the supercat forum