SL6511 replacement for SL6502

BURTON4273

I recently blew a tweeter on one of my RT-600's (the tweeter was an SL6502). After calling Polk, I found out that the SL6511 replaced the SL6502. Do you think that the SL6511 will blend okay with the SL6502 if I only replace the blown one? Also, does anyone know if the SL6511 looks similar to the SL6502 or is it going to look stupid when I remove the covers? Also, suggestions as to where I should look for cheaper (used is okay) replacements if I decide to replace both tweeters would be appreciated. Thanks!