Unusual Toy Train Paperwork

There are toy train collectors who challenge themselves to find items few of their peers own. Company paperwork is one such niche within the hobby. While all of the major manufacturers included instruction sheets and catalogs in their printed material offerings, correspondence and detailed step-by-step manuals sent to repair shops, known as Service Stations in Lionel's sphere of influence, are treasured above more common paperwork.
Pictured here is a letter to Service Station managers from Fundimensions, which was Lionel's lease holder during the MPC era (1970 to 1986). It details which locomotives are compatible with a new AC power can motor the company recently released.