I fixed one worse than that on a zero. I used JB weld. Last time I saw that bike run was about the ten year mark from when I fixed it. But if it was MY bike, I would replace the case while you could still get parts.
A standard Beta 250, since you have not ridden in a long time. It is the most forgiving. The standard Montesa would be next, but is not as forgiving as you would think. The electric start TRS could be a consideration, but everything happens faster on this bike.
Your film is correct, but what you wrote on here is wrong. Splat is short for splatter, because if you miss you will be splattered all over the ground! The zap came along when our suspensions were not as good as today. The double blip was just an extension of the roll up. The roll up will get you over 90% of what mere mortals ride as long as you `kiss` the front tire off the top of the obstacle to clear the skid plate.
Read this whole thread for ideas before you start. Ps. Pull the clutch actuating arm out and lube, after 445 years it needs it. https://advrider.com/f/threads/ty175-staring-down-the-rabbit-hole-need-a-guide.1463250/
I would assume it would be number one. Did you not take a pic before you took it apart? You should also be able to spin the shafts before you reassemble and see it work.
You could say everything 2002 and newer could be viewed as Modern in the trials world. Anything from`89 to 2000 was the first decade of water cooled bikes. So alot of learning and development through those years.
You need to pull the clutch cover and pull out the center bolt of the clutch basket and make sure it is a hollow bolt. That is the engine vent and you have to have the cltch basket in specs.
You actually have to read what I wrote. The nipple was broke off at the caliper, so I installed one at the MC. So you have to still bleed uphill. You cannot bleed down hill. Both of you are crazy. Crazy people will spend days bleeding a simple system.
Two weeks ago my God Son broke off the bleed nipple the night before he left for a 2 day event. I stole a nipple off his Dads 525 KTM and bled it from the M/C.
https://advrider.com/f/threads/what-did-you-do-with-your-trials-bike-today.644122/page-645#post-40822158