Even though it is basically the original YF-17 (ex USAF 72-1570), still the manufacturers wanted it to look like the F-18 prototype, which -- albeit of the same configuration -- was considerably heavier and with numerous other differences. This aircraft was transferred to the US Navy in early 1976, receiving out-of-sequence serial 201570 (one of many such serials), as seen in this photo. The Paris show number 42 can just be seen below the wing.

This was the second and last YF-17 built. It first flew as USAF 72-1570 on 21 Aug 1974 and was transferred to the US Navy in early 1976. It received serial 201570, which it carries in this photo (one of the US Navy's many out-of-sequence serials). The aircraft was in a design competition with the F-16, to which it lost. The design then lead to the development of the F-18. The aircraft is seen here being towed from the static park to the flight line ready for a very sprightly display.