After much research I have finally completed locking my transmissions differential. Here's how to do it.
First of all, this technique will only outline the procedure for a PEERLESS 800 series transmission. Other transmissions will use similar steps, but will require different fabrication techniques.
You will need to acquire two 15 tooth spider gears for this procedure.
Hint: if you have a single speed transmission lying around collecting dust (the ones used on vari-speed belt systems) you can grab these gears out of it. They are the correct type, assuming that the single speed transmission is also a PEERLESS!
Once the bulk of the grease is removed, you'll need to remove the drive pin. To do this, tap out the small roll pin that keeps the drive pin in place.

Next step is to knock the drive pin out

You will need to drill a hole through the drive pin. This hole will be for bolting the new spider gears into place and holding them. You need to measure for the exact middle of the pin and drill your hole to fit a 5/16 bolt.

Replace the drive pin and reinsert the roll pin. Then put your spider gears in place, run a bolt through, being sure to use washers on either side, as well as a lock washer and nut.
Warning: Do not forget to
lock the nut on the new bolt you just installed. I chose to drill a hole straight through the nut and cotter pin it. See, told ya I was a hack! LoL But, in my defense, this was done before I got my first welder.

Degrease the entire interior and gears. Put Lucas gear oil in. Fill the bottom case about 1/3 of the way. Put RTV sealer all the way around the edge of the case and put it all back together.
And that should do it!
I've tested it and it works fantastically! If you're looking for a huge upgrade in traction, braking, and power, THIS is the WAY TO GO.
Here's a video to watch as well:
Next I'm going to do the same thing with my other tractor which has a 930 peerless tranny in it.
I'll also do this with my Foote/Dana/Spicer 4360 as well.
MM