Some I just put on with nothing under it,and I have done some lately with a black permanent
marker and will really make the pattern stand out,either way looks good to me.As far as the scales don't try and pull them off,I rub them with a rag in the way they lay before gluing them down
to get most of them off and then after the glue is dry I will rub them again the way they lay and it will get them off.Sometimes I use 000 steel wool just don't bear down to hard.Then I just seal right over them,each time the sealer dries I will rub them lightly in the direction they go once and seal again after several coats they will be smooth as silk.Some folks put them on the edge also
but I just glue them on the top and trim off the sides and clean up the glue that ran down the edges.Hope this helps.
You can glue them down with Elmer's wood glue or Tite Bond 1/2/3
I would suggest if it is your first try, use Elmer's or TB1 it give you more time to make sure the pattern is down the middle and to be sure you get all the air bubbles out.I then rap starting at the handle wit ace bandage keeping it tight and straight as you go.Another set of hands helps but you can do it on your own ,just take your time and keep it straight with no wrinkle's.Good luck.
One more thing you need to wet them first to make them limber.
Pappy