Ok, so we were at a regional and it just so happened that we lost our radio transmitter. Not the OI but the little transmitter with the metal antenna on it. It just so happens that we have the transmitter from last year and it does have the same blue print along with the model number RS-422. I would like to know if it is possible (and legal for competition) to use last years transmitter. Thanks in advance for the help guys.
I don’t know for sure, but there have been reports of problems with last years stuff with the new controller. 
According to innovation first pre-2004 control system parts are NOT compatible w/ the 2004 control system
Stolen from the IFI FAQs:
Q: Can I use older radios with the 2004 Control System?
A: Yes, all Innovation First radios will work with the 2004 Control System.
However, the “Blue” radios from last year and this year have significant improvements over the previous years’ “Red” radios. It is not recommended that Red and Blue radios be mixed. You can only use 2004 radios at the 2004 FIRST competition