I don't know if it can be removed either. But there were a number of welds around the ring gear - so maybe it can be removed, but it's not worth it.
$50 Holy Cow! - BUY A NEW ONE! To me that is a super price! I'm sure that old ring gear is removable, but why screw around with it for that price! I was thinking a couple Franklin's at least for a torque converter.