I wasn't able to locate the Jayco #0760392 unit (google).
In 2005 Jayco installed two different styles of IOTA converter/chargers, it depended on the TT model. One style was mounted directly to the back of the Load Center (breaker/fuse panel), the other was located remote from the Load Center. I would confirm that the #0760392 matches your style of unit. The IOTA units supplied in 2005 were 2-stage charging units.
I also agree that the newer 3 or 4 stage units are the way to go, they provide enhanced battery management resulting in faster charging and longer battery life. If your existing IOTA converter/charger is mounted directly to the back of the Load Center, I'm fairly certain that only a 2-stage replacement is available.
My 2005 Eagle IOTA converter/charger was mounted to the back of the Load Center, all I did was disconnected the existing IOTA wiring from the breaker/fuse panel (left the IOTA in place), and installed a new 3/4-stage Progressive Dynamics PD9245C ($200 or less) remotely and landed the wires on the breaker/fuse panel where the IOTA wires were.
Reference thread: http://www.jaycoowners.com/forums/f3...rade-2512.html
PD9245C: PD9245 45 Amp RV Converter / Charger from Progressive Dynamics
If your existing IOTA is mounted remotely from the Load Center, the R&R is rather simple.