Bob Hackett
The only abrasive blasting I would do on something like these would be along the lines of walnut shells or something else that will attack the rust but not the steel.
Sand blasting or even glass beading will leave a toothed surface that will stain easily and collect things like pitch and sap faster than a surface that has been sanded in line with the blade.I speak from experience on this.
My advice is to leave the blasted surfaces for paint.

What I have done for work saws(like those we used for dock work over salt water)is too take either a straight line sander(like those used for auto body work) or in extreme cases a belt sander to the areas above the teeth.Look at a decent new saw and you can pretty well tell what grit you should start with.Where you go from there is up to you.
Just be aware that a thin saw blade will heat up quickly if you don`t keep the sander moving and/or cool the steel with air or water.