Here is an early MWT advertisement for the NS702:
And here is a much later mention of the NS702 by the GPO as a representative marine receiver:
There does not seem to have been a lot of consistency when it came to the use of the mythological names. Atalanta appears to have been exclusive to Mimco. On the other hand, Hydrus and Argo were MWT names for receivers that had no Mimco versions. Apollo appears to have started as the Mimco name for the MWT N2050. It was not used by MWT in early literature for that model, but later advertising had it as N2050 (Apollo).
Cheers,