I am Ted Hartson, also WA8ULG and closing my lab I kept a pair of HP 5060 Cesium for years at my lab and thought my life would be more complete if i had an HP 5371A. If you are not familiar with this box I attach it has virtually zero hours of use. http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1989-02.pdf I am now retired and have closed most of my lab.  I would sell this for $1000 plus shipping from Arizona. Contact Ted Hartson 928 635 1927