hm
so if I remove both of those two tran_bank lines, the LED goes permanently on
if I remove JUST cart_tran_bank0 = and NOT cart_tran_bank0_dir (because probably we do want to flag it for output mode) , the LED goes permanently off and my logic for turning it on seems to be ignored when it ought to be triggered 
but! I can use the attached button, just not the LED, so that's something
Maybe I'm meddling a little above my skill level here.