RFB query: Balao Class Availability

[HMCS]

I am consistently offered a Balao Class boat after 3 patrols in a Gato; that's not bad, but they generally weren't available in numbers until May of '43. Is there a file I can edit somewhere that only makes them available after that date?

Or should I be posting this in the sh4 Mods subforum?

[ancient46]

Look in the NSS_Balao.upc file in the Data/Submarine/NSS_Balao folder.
UnitInterval= 1943-02-04, 1963-07-11 is the line to modify.