Elbe-Weser marine pilot transceiver (ca. 1960)

Nothing, zilch, nada from Google on this bright yellow, portable, NBFM 70 MHz receiver/transmitter from Philips duly labelled “Fabr. Nr. LO 601” and “Type 4RR105-01”. It goes by two other names as well — having peeled off a sticker applied over another one on the side of the chassis, I was able to read ‘LO 777’ and ‘4RR110-01’ in the respective boxes. Fortunately, the radio is not a total mystery. Archives indicate that it was used by pilots assisting with ship navigation around the light vessel ‘Elbe 1’ in the (huge) Elbe-Weser area in northwest Germany.