Got the Maggies out of storage (well, laid down behind the sofa in the music room where they've been for about 8 years)
Got the stands from the Maggie 2.5Rs fitted, set them up and listened to some music. Sounded a bit dark, so pulled the tweeter fuses - sounded just the same. Not good. Ran a REW frequency sweep...oh, dear dropping like a stone after 7kHz. Pulled the fuses again and ran another sweep, identical result. Checked the fuses, both OK. Put the fuse back in on the left speaker and ran a sweep just on that channel...just the same. Noticed that the fuse seemed a bit loose in the holder, so clamped it tight. Ran a sweep on that channel...Bingo! all OK. Did the same on the right channel...still dropping after 7kHz. Damn! Pulled the fuse and got out the Deoxit which I bought to clean the 15 silver plated contacts in the AMI jukebox pulse convertor (1959 high tech). Put the fuse back and ran a sweep on the right speaker...Bingo again! So, both fuses now "deoxited" and both speakers now good up to 16kHz which is as high as they ever went when they were new.
So, hopefully the old ladies will behave themselves on Saturday!
Deoxit is ridiculously expensive but in my experience it does work - definitely not foo!