I have a early model cobra 25 side mounted mic.I want to do the 520mosfet mod on it but cant find info on it.I was wandering if it would be the same as the 520 mod on the cobra 29 ltd? Have heard that it was the same and that it was not,I got to know for sure before I try it.I have done the mod on a 29 ltd st and it worked fine.Thanks for any help.