The original HBR-14 article in 1957 used a homebrew interstage 1610 kHz
transformer
which should be easy to duplicate.
Instead of the 100 kHz IF transformers, the 85 kHz IF transformers from a
defunct
BC-453 are a good choice. The 85 kHz BFO coil can also be used. There are
several
receivers on the HBR website that show the use of these transformers.
73, Kurt, W6PH