I need help in locating a transmission fluid leak, need help from the veterans Options

[6strngs]

alright, so I had to pull my transmission to replace my rear main seal a while back and after I got everything back together I've noticed I have a leak coming from where the driver's side axle where it meets the transmission. I've left it be for several months just topping the fluid off every couple of weeks, but I'm ready to fix the actual problem now, but I'm just not positve on what it could be. That's the main reason I haven't already fixed it. I've been pouring over my toyota factory repair manual for the last 3 hours and I've come up with 3 possible causes for the leak, but I'd take any opinions from anybody who knows more about this transmission than I do or any info on any of these 3 things.

My first guess is, at the end of the axle is a snap ring which is supposed to be replaced when re-installing the axle. I didn't replace this ring as I didn't know it needed to be replaced. I took some pictures of my manual to show what I mean if that isn't clear:




the next thing I think it could possibly be is the O-ring for the differential case bearing retainer. Basically where the axle connects to the transaxle is this piece with 6 bolts going into it. I had a hard time removing the axle and I figured those bolts needed to come out. So I had removed them and had even pried on it! There is an O-ring under it that is a non-reusable part that I think could possibly cause the leak. here's a pic (the letters are blurry, but you can still somewhat read it. it's the O-ring underneath the "differential side bearing retainer", the diamond, which just looks like a blob in this picture, indicates it's a non-reusable part)



Lastly, I guess there is an oil seal inside the same bearing retainer. This seems the most likely culprit to me. here's two pics showing the pictures and the text next to them regarding this oil seal:




So what do you think? Would those three things be the only 3 things which could possibly cause a leak right there? I'm also looking for the part numbers for these 3 parts. I've been to a parts store asking for them and they couldn't find any of them, and I've looked online on 1sttoyotaparts.com's catalog and couldn't find them, so I'm guessing the only way I'm gonna find them is with specific part numbers. so, please, HELP!