If you have a welder available Ben, this might be the best option for you at this point in terms of not having to wait:
" Tired of fussing with those clips, Marlin Czajkowski, of Marlin Crawler fame, started thinking. The clip isn't intended to keep the Birfield from pulling off the axle and heading outboard from the centerline, because the Birfield's stub is stablized and constrained by the hub and spindle. The only real purpose for this clip is to prevent the axle from sliding out of the Birfield, toward the center, and into the differential. Normally, the axle floats inboard and outboard a small amount, constrained by the clip at one end, and a bigger c-clip on the axle.
The tack weld should be placed in the location shown in the picture, on the splines that go into the 3rd member. The last 1 3/8 - 1 1/2" of the splines should be left clear. The weld needs to ground down so that it is the same height as the splines.
A few more moments thinking, and Marlin had his solution - a couple of tack welds at the differential end of the inner axle shaft. These tack welds prevent the inner axle shaft from jumping out of the Birfield and into the differential, and you'll never have to fight with those little circlips again. Trail repairs just got much easier... and if you want never to worry about breaking a Birfield again, you can install Marlin's new Marfield joints. Marlin tacks two places on the axle, just over one and a half inches outboard of the inner end of each axle where it slips into the differential (red dots in the diagram). Any old welder will work: arc, MIG, or TIG. Just tack it lightly, you want to deposit a small amount of rod but minimize heat transfer. When you reassemble, you can leave out the end circlip (blue arrow in the diagram), but be sure to include the square-shouldered clip (green arrows in the diagram)."
Link:
'Marlin Tack' Inner Axle Retainer - Toyota Cheap Tricks - Trucks 4x4 @ Off-Road.com