I read on another thread that it is somehow illegal to swap out the crystal in the Tx for another channel. Did I misunderstand this?

One of the reasons I'm asking is that upon arriving here in Japan, the pres. of my local club informed me that the frequencies I had on my Airtronics VG6000 (27) and VG400 (29) were not legal in Japan (they use 72 and 40Mhz but not these particular bands). The solution? A fellow club member gave me a channel 18 set of Tx and Rx dual conversion crystals from Sanwa (the good people who actually make Airtronics radios) and voila, I was off flying. I've salted the other crystals away for my return to the US.

Should I be expecting a visit from Homeland Security upon my return?