Well KM, the Tench should come with the ST on 1945-01-01. Look through your files though and double-check the "UnitPart 1.Compartment 1.EquipmentSlot 1" for the presence of "IDLinkEquipmentIntervalDefault2= 1945-01-01, NULL, STRadarAnt". Then look at "UnitPart 1.Compartment 1.EquipmentSlot 6" for the presence of "IDLinkEquipmentIntervalDefault2= 1945-01-01, NULL, ObsPeriscopeHeadST". I do not remember what they'll look like in the Save file set... The "Upgrade" should have a line "IDLinkUpgradePackElements= STRadarApp, ObsPeriscopeST, STRadarAnt". Those are all associated with the conning tower in the UnitParts9Tench.upc. In the Submarine Tench.upc will have a section
[UserPlayerUnit 1.UpgradePackSlot 1]
ID= UpgSurfaceSearchRadar
NameDisplayable= Surface Search Radar
Type=NULL
AcceptedTypes=BalaoSurfaceRadars, BalaoSurfaceRadarsImp, DummyRadar
UserCustomizable=Yes
IDLinkUpgradePackSlots= EqSlot42, EqSlot43, SurfRadarAntenna
IDLinkUpgradePackSlotsIntervalDefault1= NULL, 1943-05-31, SJ Radar Balao
IDLinkUpgradePackSlotsIntervalDefault2= 1943-06-01, 1944-12-31, SJ-1 Improved Radar Balao
IDLinkUpgradePackSlotsIntervalDefault3= 1945-01-01, NULL, ST Radar
All of those are necessary for the ST to function. You do have to be at Radar Depth, Observation periscope up, and the radar on and on sweep, no waves washing over the scope head. Notice that the radars are now done like the AA guns as mazzi showed for the deck gun, and that all parts are listed, and the "Upgrade" should now work, even on the Gato and Balao -BUT- no early purchases because of the need for multiple parts in two different files, and we can't get them to link together, so we gave up on that... but that should be with the Tench, and during testing for v1.46, was fully functional on multiple computers. It ~looks~ like you have it all there except you are not showing a listing for the ST Periscope Head... ??