If you know which issue of RMJ, MRding, or ProtoModeler you want to download, type in

http://magazine.trainlife.com/wp-content/uploads/2017/08/abc_yyyymm.pdf

where abc =
  rmj = Railmodel Journal
  mrr = Model Railroading
  prt = Prototype Modeler

and yyyymm is the month and year of the desired issue  For example,

http://magazine.trainlife.com/wp-content/uploads/2017/08/rmj_199007.pdf

will download the August 1990 issue of Railmodel Journal.

John Monrad