These are copies of the hard to find Service and Repair Manual for the 1946-49 Lionel Electronic Control Unit first released in 1946 and discontinued after 1949. It contained a high frequency oscillator and fixed front panel with two groups of buttons which controlled several specific fixed frequencies which operated tuned frequency modules located in specific locomotives, tenders and cars allowing for remote control anywhere on the tracks; of couplers, whistle, direction or car operation. An addendum to this manual has been added to include the specific wiring diagram for the 4671W Tender that was included in the "671R sets and a new schematic diagram drawn to current standards using Orcad Capture CAD software; ( easier to understand than the original pictorial drawing ), a total of 19 pages. The manuals are shipped in a 9" x 12" envelope to keep them flat. Shipping and cost of envelope is free. Payment Method: I accept PayPal only.