Staining posts and balustrades...

We have a 100+ year old old victorian staircase that we stripped of paint to restore the wood surface.

We polyurethaned the treads and risers while repainting the balustrades white.

Our plan is to stain the newel posts dark brown and give the mahogany railings a clear finish.

Questions:

1. What are appropriate finishes to use for staining and protecting the newel posts? (we are looking for finishes that are relatively easy to apply and that will stand up to wear-and-tear while still looking period authentic)

1. Similarly, what recommended finish should be used on the railing?

Thanks!