Charlie You can buy brand new Honda "Monkey" bikes as they call them now. 125 cc 4-speed with hand clutch. Little bit more expensive than they were in 1970, like $3999 msrp.
My Brother-in-law still has his Trail 70. I got a Mini-trail Z-50 for Christmas of '67, was 13 yrs old. Was my way to/from work for the BTO 1-1/2 miles away. No lights, no speedo, so no license plate, some self-appointed Protector of the Road lady stopped me on the way home and read me the riot act about my "vehicle" was illegal, I was illegal, and she was calling the Sheriff soon as she got home. Humm, Guess I better drive my 5000# Farmall Super H to/from work, Me and the tractor ARE legal. Anyhow, Trail 70 ran 45, Mini-Trail ran 25, 30 maybe, even my Scrambler 70, CL-70 topped out at 50, but it was licensed, lights, speedo, turn signals, but couldn't pop a wheelie at all.
I don't have the p/n for the seals but you might want to get two when you find them. That's what most people are doing now. The OEM seal may have been thicker but the seals available today are apparently thin enough to use two.
Maybe someone will chime in with the p/n for you. They are available at some auto parts stores.
Or you could have your local parts store cross reference that number.
I know for such a tiny seal they are not cheap!
TIP: When you install them, be sure to not drive them in too deep or you will plug the return oil passageway in the casting. If your shaft is worn some, even 2 of them may not solve the leak. On my 126 re-build several years ago I installed 2 and it still seeps a little enough so I keep a piece of shop towel secured under the assembly when in storage.
So I got this 128. Before I replaced the carb, I was having problems with the carb only wanted to run on choke. The carb was a 26# fixed high idle. I've now put a 30# cheapo and it can only run with choke on. I'm also getting smoke coming out of the exhaust. I would think it could be the fuel shutoff valve as that is a bit messed up and could not be open all the way. - edit - after taking off the fuel line to the carb and putting into a bucket, it has a nice stream of fuel getting to the carb - edit -