Answer:
A little over 600 wooden WWII PT boats were built; and approximately 9 exist today, on display and/or under-going restoration in various places thru-out the US. These 77 & 80 foot boats were built by Elco and Higgins companies during WWII. Elco built nearly 400 of them, and Higgins built close to 200 of these craft.
Nearly 200 Aluminum Vietnam War Swift Boats (officially designated PCF-Patrol Craft Fast) were constructed during the Vietnam war, commencing about 1965. Two are known to exist today for display purposes: one at the National Museum for the US Navy in Washington DC (East Coast) and the other Swift Boat is on an active US Navy base in Coronado CA (West Coast). All of the Swift Boats (PCF's) were built by the Seward Boat Company of Louisiana.