$100 is a steal for these, IMO.
Plus IIRC there are actually two different tweeters, one pair of each. To do a proper restoration you have to source the correct ones. Mine had one bad tweeter which I just replaced with a generic. I figured one out of four, it would only make a 25% difference in coloration (I matched the resistance of course). I couldn't hear a difference between the proper one and the repaired one.Rectilinear IIIs are a lot of bang for the buck. I think they are currently undervalued. The tweeters are quite good for paper cones (aluminum dust caps) Used ones are still available if you’re willing to do some searching.