I bought a 1947 Royal Quiet De Luxe (first typewriter!) and, surprisingly--at least to me--everything seems to work almost flawlessly.  The only issue is that it will not advance the line by pushing the return lever unless the variable line spacer button is pushed in slightly.  Otherwise, it advances the space on the outside of the ratchet, but the platen doesn't turn.  I took it apart, and it seems as if the teeth on the fractional cylinder end don't really catch on the inside of the chrome ratchet end, or whatever that piece is called.  The teeth are so tiny that it's hard for me to imagine that they ever really could have, but they must have.  The manual at typewriter database says I have to replace the whole platen, but everything else seems good.  Do I just need to get lucky and find a parts machine, or is there some way to, perhaps, cause that variable button to stay in?

Thanks for your help!