I've done FAA written ATP too before I came back to AU but I wish to apply for either QF or
VB so I am starting a class in Jan to redo all CASA 7 subjects...I am flying for charter company in NT, I've got 800TT now but probably it'll take me another 8 months or more to reach to 1500TT, then only I can do ATP cheackride to obtain full FAA ATP..I am already back in AU and going back to the States just to do Chkride isn't practical at all..and then come back to AU and resit Air Law, it is easier for me to redo all 7 subjects and if I finish within 2 months, I can even meet the minimuns to apply for QF or QF link with CASA CPL/MEIR, ATPL theory with 500 PIC (Most likely they won't even reply but atleast I would meet the mins)
However a friend of mine has full ATP ticket with 2000+TT, he doesn't wish to go to the airlines so he only did Air law exams and RFDS took him..so it also depands on who do you wanna fly for...regional airlines such as Air North, Pearl Air, Vicent, Mcair Sky Trans etc, probably they wouldn't care if you only have conversion ATPL but atleast you have to meet their mins 1500TT, 500 ME PIC, higher than QF or QF links.