The archives in this case being a dust covered cardboard box on a bottom shelf in the far corner of the 'Lab'.
The chassis work by Melissa & Doug represents the 'Early Davey Functionalist' era that predates the 'Drug thru the Hudson' look of the early 21st century.
It is a simple remote controlled 100K linear pot attached to some RCA plugs used explore loading options for MC cartridges. At one point the concept piqued the interest of a well known Stereophile reviewer but upon borrowing the unit, he was terrified to plug it in to his system so into the archives it went.
The remote controlled pot was the handy work of of our good friend John Chapman and the concept evolved into the Opti-Load which replaces the pot with a relay controlled resistor matrix.
Technics RS-1500US - http://www.itishifi.com