Chuck, Don't waste your money it is the 50mm. They still have the BF-33 but it is an Ashi and different form. I bet those starr's are old stock put back in service.
Starr's are the bad version and i have seen 4 ohm and 16 ohm starr's disintegrate. If an engine has one that has not, I bet it was replaced at some point so it just has not started to disintegrate yet. This goes all the way back to Strock as SM with the notices to stop using them.
Now the whole short the coil issue to blow audio amp, I have not seen. I have replaced plenty of heavily damaged speakers with board audio still fine. The coil is isolated from the magnet. I know this because I had a speaker where the magnet came off the frame. Can a speaker short... sure. The shorted speakers I have seen looked perfect, but blowing whistle usually would shut the board down. Usually it is the coil wire lead going to the solder pad though. Runs too close to the frame and vibrates into the frame when generating sounds and ultimately damages coating and shorts. G
