The NMRA published reprints of the January, 1943 and January, 1953 Official Railway Equipment Register (OER) several years ago. They are likely "sold out" at NMRA HQ but some may be available at swap meets or from used book sources. Naturally there are many originals that show up at memorbilia swap meets and on electronic sales.
Also there are several original OEMs in the archives at WHQ.
As far as CD's I'm not aware of any myself. The 1943 issue has 1066 pages and the 1953 has 826 pages.
At least some of the Official Guides (OG) have been put on CDs and made available
thru ads in Trains Magazine, etc.
