Here is the stock ROM / firmware for the T-Mobile version of Samsung Galaxy Tab P1000. This ROM contains no bootloader which is good as it would not brick your Tab in case the firmware is not properly flashed. Flash it in Odin from the PDA button, no .pit file, nothing else.
Download the firmware from here. You can the T mobile modem’s bin file from here. Credits to the rotohammer from xda developers. [via xda devs]