What?! For the 61/67A750?? The 1005.3 FW has been on their site as a download since May of 2008!! Either you've been looking at the wrong website or you're just coming out of a 4 year coma
As for waiting on your TV to arrive, what exactly do you mean? Repairs or you just buy it? If you just bought it (obviously not new), there's a good chance it already has a FW more recent than 1005.3 installed on it already.