the cap ship numbers are altered in the 'RESEARCHSUBJECT_MAXCAPITALSHIPSraceUpgrade.entity' files, the logistics/tactical/starbase/mines slots are in the 'PlanetTYPE.entity' files, and you can also alter the fleet supply in the 'RESEARCHSUBJECT_MAXSHIPSLOTSraceUpgrade.entity' files, as the gameplay.constants are replaced EACH patch
and the entity files should be first copied to another location before you try to txt the files.
it is also a good idea to create a mod folder with your changed files in it
hope this helps
harpo