Probably buy a used hpx for 1-2k
You know something the rest of us don't? I challenge you to post a single listing for at least one like mine for under 4K in Western Canada, thats double what you think they can be bought for...I think you might be in for a bit of a surprise...even a used kiddy Peg Prego electrics are @500 bucks lol.
As for what cratered, went out after supper, figured do a bit of testing and diagnosis, with the case already buggered, well not much worse can happen now, and tried throwing the diff lock in, made no difference, then threw it in reverse and tried that, was a soft clunk and everything went as it should. Back into forward, went a few feet and clunk with the grinding again. Back into reverse and figured I'd park it more out of the way, couple of hundred feet no issues at all. Then just for shits and giggles back into forward and presto everything as it should be. Was only a couple hundred yards past the bins to the shop so figured what the heck, everything would still be covered with oil and nice and slow got it close to shop and out of my way for the time being. Closer look at the tranny case where it split, reason it broke both sides, is the hitch mounts straddle the flanges of the case and so when things piled up it had to blow both sides. Only cracked the bottom part so not sure if I can weld them up or not.
Definitely the diff that piled up, possible something ultimately went thru the crown and pinion, dunno, just guessing at this point.
Had to go rake hay and be busy wacking out some horsey hay for the next couple days, maybe when it rains I'll have time to look further.