Well, there's four different Jaguars in the Middleweight line. Each has similar yet different equipment. Full tanks vs. slimline tanks, different rack styles in different years, stainless fenders vs. chrome fenders, etc.
The Jags are generally considered the top of the line Middleweight, these things were decked. The Corvettes are sort of a middle-range bike, some neat and high quality extra equipment, but not a lot of it. The American line was a basic bike, but not entirely a budget bike, these had solid parts, but didn't come with anything extra to speak of, no lights or racks or tanks. (With the exception of the Deluxe American line.) All these bikes used the same frame, with the exception of mounts for caliper brakes when so equipped.
For '62 the retail (zone 3 to get exact) for these bikes equipped as 2 speeds: Jag IV, $87.95. Corvette, $79.95. American, $62.95. And for comparison, the lowest price 2 speed middleweight was the Typhoon (painted rims, budget stem and pedals, etc) at $52.95.
Cheers, Geoff