Hi Tony Personally I do not have the design details you are seeking ,but I can direct you to the inventory of reports issued by the Radio Branch of the National Research Council where you may find something useful. NRC Radio Branch exercised overall responcibility for design ,but manufacturing was the responcibility of REL.
There are two series of reports PRA-1 through 135 and PRB 1 through 152. These are listed by subject and are accessable to the public (subject to archival restrictions).I cannot recall the links to these lists but my printed copy has an URL
http://cat.cisti-icisti.nrc-cnrc.ca My personal visit to NRC CISTI in Ottawa was not a huge success. Good Luck Brian