Like was said.. when it works.. its golden.. when it doesn't.. you are calling 15 places looking for parts or a gear tranny.
I read a few antique mags.. and you usually see one or two places that part out, or buy SOS tranny parts. So some parts are available.
Kinda reminds me of dual power on the 8000's If it works, cool.. if it doesn'.. leave it and use the low range!... cheaper than fixing, as some of the tranny gears go for big money!
Like I said.. if it was a parade/show machine, and the SOS woked.. I'd be happy... if it is a worker... and the price was right.. id get it.. keeping in mind that I may need a tranny if it ever fouls up.. etc. That said... gear trannies do die.. just never can tell how your luck will run on old iron.
Soundguy