Batboard

Has anyone ever considered painting the bottom of the 900 Spectra preselector with silver paint while sweeping it to lower its frequency? Looks do-able except the first resonator which is covered by a metal shield. I have also been thinking of replacing the preselector filter with two of the Murata filters with a preamp in between. Electrically this isn't a big deal but mechanically it is tough because of the way the module is assembled. I have a junker I think I will try it on. Also considered building a replacement module but that would be so expensive it would be easier to just look a different radio altogether. So, who has done some serious Spectra hacking and what did you do?