Revell has issued so many Constitution kits over the years that it's tough to sort them all out. When I first read sumter III's initial post my inclination was to think he was talking about the "Simplified Series" kit - the mid-sized version between the original, 1/192-scale one from 1956 and the big, 1/96 one from 1965. But the 1960 date on the instructions throws me.
According to the bible on the subject, Dr. Thomas Graham's Remembering Revell Model Kits, that mid-sized version (22" does sound about right for it) was originally released in 1969 and remained in the catalog until 1975. (His coverage stops in 1979, so he's no help with that printing date of 1990.) He gives the scale as 1/159, which sounds about right.
That kit was part of an effort by Revell in the late sixties and early seventies to drum up some interest in sailing ship models among people who didn't normally build them. (Olde Phogies like me will remember that American model manufacturers generally were having a hard time in those days. That was when Aurora went out of business and Monogram, having been taken over by Mattel, virtually dropped out of the serious scale modeling scene for several years.) The series was promoted with phrases like "Build a Legend In a Weekend," and the kits (the others were a Cutty Sark, a Thermopylae, and a Mayflower) featured such things as low parts counts, injection-molded "shrouds and ratlines," and lots of detail parts cast integrally with the decks. (The Constitution, Cutty Sark, and Thermopylae were, in terms of overall appearance, scaled-down versions of the big 1/96 kits. The Mayflower was scale up from the excellent little 18" one.) Then, much to the surprise of ship modelers, Revell issued a brand new kit in that series: the yacht America. That one wasn't particularly simplified; it was a mighty nice kit - and I wish it would get reissued.
As I remember, the easiest way to identify that "simplified" Constitution was by means of the guns and the gundeck (or, more properly, maindeck) - the one that's only visible through the big hatch in the waist). In the "simplified" version it was a relatively small part that only extended slightly fore and aft of the hatch. (In the 1/96 kit it's made up of three pieces, and runs the full length of the hull.) The guns (or at least their carriages; my memory's vague on this point) were molded integrally with the deck; the maindeck gunports fore and aft of the waist were molded shut.
Bottom line: if that's the kit in question, Dr. Graham's stated scale of 1/159 (this was the "fit the box" era) is probably about right. But that date of 1960 on the instructions doesn't make sense. (In 1960 the only Constitution in Revell's catalog would have been the grand old 1/192 - or 1/196 - kit from 1956. Is it conceivable that the instructions don't match the kit?
Sumter, do you have a kit number - preferably from the box rather than the instruction sheet? We could look up the number in Dr. Graham's book.