I ran across a reference to this on FB. It appears to be from 2008, so may be well known or obsolete material. The other interesting info at the end of the article is the contact name and info about someone who restores or works on tape heads. Might be interesting to at least contact and ask if he's still around http://www.wendycarlos.com/bake%20a%20tape/baketape.html Contact John French, at JRF Magnetic Sciences (973-579-5773) for further details on magnetic tape head restoration and storage, and other related services and products. FB page with the info. https://www.facebook.com/ReelToReelTapeRecorders/photos/a.532104240183459/3… The fellow who does a lot of tape recorder (reel to reel) repair has a FB group worth dropping in on. This is the link to a photo with a pretty bad Ampex head. thanks Jim