Offhand I'd say it's just a matter of swapping the gauges in each aircraft's panel.cfg.
I have very few unmodified panel.cfg files but if you tell me which stock ADF you don't like and which stock RMI you do like I'll send you some instructions.
Or you can just get cfgEdit (free) and do it yourself.
http://www.cfgedit.com/ (I think it's in the library, too.)