Gents,
All great suggestions, thank you very much!
I'll share with you my odyssey: I posted this and selected "alerts," but for some reason I never got an email from the forum. Prolly need to check my spam filter settings...but anyway. I got back on here today and saw your responses.
My first COA (Course Of Action) was to visit the local transmission shop and ask if they could remove the flange. No dice, he says, I'd just rip it up trying to take it off and I'd rather not...everyone else local wasn't comfortable with attempting it.
Next, I looked on CL and found a 99 LC being parted out, but it was about 5 hours away in Asheville and had taken a pretty gnarly broadside hit, so I wasn't sure the TC had survived that wreck without serious damage. That, and the owner wasn't exactly helpful with info. Plus the drive time...to quote Gilda Radner, "never mind!"
I considered taking a grinding wheel and removing the dust cover/flange in just that spot to press a new stud in (I had to cut the previous one IOT remove the driveshaft--the nut was halfway on, seized, and the stud would spin even though it had been gooped-up with JB Weld by the previous guy who'd worked on it), but figured the dust shield was actually functional since the seal was in good shape after 276K on the clock. I also considered purchasing an entire TC off a parted-out vehicle, putting in the soon-to-be-discontinued Marlin Crawler gear set, and then just swapping the TC when I was done. But again, how much time & effort was this going to end up being, simply because the previous clown was too cheap to pay for a proper repair, or the shop he used was shady AF? I'm sure he was quoted a similar $500 + labor amount to replace that flange, so he probably deferred and I can't totally say I blame him. But...in order to get it at least *RIGHT*, I felt I needed to get back to some semblance of a baseline repair before doing more upgrades.
So I have time, and I have *some* money, but neither in infinite amounts. I could drive to hell and back to search parts yards etc. I like the idea from DTCsk8er about welding it in place, but like I said that stud was stubby now since i had to cut it. So that was out.
In desperation (the front driveshaft replacement was SO EASY by comparison!!!), I started searching overseas for my part, as it is a discontinued part by Toyota. Thanks. 80-SERIES PARTS FOR DAYS from aftermarket vendors, but if you have a 100 you're just not quite the cool kid! I stumbled upon "PARTSOUQ.COM" that had the very part I was looking for! Not cheap, exactly ($356 + $26 shipping), but not horrible considering it was gonna cross the Atlantic from the UAE to get to me! I was skeptical ordering from them, as my experiences in that part of the world haven't always been "positive," but like I said I was getting desperate. My internet research indicated that guys on other forums had used them to good effect, and that they were a legit company that were thorough in their communications, even though their English skills might be slightly off. I made sure I paid with a means that had a good fraud protection policy, crossed my fingers, and waited...
Turns out I didn't have to wait long, as I got multiple emails from PARTSOUQ confirming my order, then letting me know my part had been picked & packed. Finally, I got separate shipping notices from both PARTSOUQ and FEDEX, both with tracking numbers, and an estimated delivery time. I ordered on Sunday (after saying my prayers and all) and the part was at my door Wednesday! The ONLY gripe I had was that the packaging could have been better: the tube at the end of the output shaft, opposite the flange, had punched through all the packaging and was sticking out. Fortunately I was undamaged but for that much dinero, I'd have liked a bit more protection. But OVERALL, I was impressed and wouldn't hesitate to do business with them again, especially b/c some 100 series parts are a bit tougher to find.
Thanks again for your help/suggestions! I'll let you know how the rest of it goes!