PT728 is a twin-engine British Vosper design that was built in the US. It's been around for quite awhile. I believe it was a "Ride the PT' attraction in Florida for many years. For its tourist attraction role it was cobbled up to resemble a larger, 78' Higgins PT.
THe "real" PTs were built by Elco in New Jersey and Higgins in New Orleans, plus prototypes and a single squadron (18 boats total) of an operationally unsuccessful design built by Huckins.
All three manufacturers incorporated the same basic requirements---- three V-12 Packard marine engines, two twin-fifty machine guns in turrets, four torpedo tubes, and the ability to carry and launch depth charges.
Outside of that, the three deigns were very different.
The Huckins boats were by far the best built and had the best ride which made sense given Huckins long history in the yacht business. In fact the Huckins PTs were somewhat derisively referred to as "yachts." Some references say the prototype Huckins boat had 4 engines, but the production models apparently had three like the other two manufacturers.
The Higgins was (arguably) the fastest and most maneuverable but had the wettest, roughest ride and the worst crew accommodations.
The Elco proved to be the best boat for the mission as it was the most successful compromise of speed, maneuverability, good ride, and good crew accommodations.
I have spent hours crawling around on and in the restored Elco boat at Battleship Cove as research for my current project. I've ridden on the now-fully restored, Packard-powered Higgins boat in Portland. To my knowledge none of the handful of Huckins boats that were made still exist.
Contrary to popular opinion the US PTs were not made of plywood, and their engines were not "P-51" engines or any other type of aviation engine although they did use high octane aviation fuel. The Packard 4M-2500 did have its roots in an aviation engine, however, the famous Liberty V-12 dating from WWI.
Way more than you wanted to know but I've got all this stuff branded on my brain now so it's easy to spout off.