Steve,
You are so right. One of the RCA's had leader in good shape, so I took it for a tentative spin last night, and a lot of the magic is still there.
All the Mercs and most of the RCAs are going to get leader fore and aft before serious playback begins, compliments of your great sticky on tape basics, I have new leader spools and that spiffy Ampex splicing block on the way to take good care of these gems.