You will be able to match the finish adequately with any polyurethane, after staining to match. Pick up several sample size stains from any paint store, try them on a scrap of the wood you are using. When satisfied with the colour, stain your piece. Leave it a day, then apply several coats of a wipe-on polyurethane. That will give you a smooth, semi gloss finish, just like the rest of the woodwork. If your coach still has its original finish (15 years, not too likely), and you don't like the contrast, it is a simple matter to keep going and freshen up the adjacent woodwork. The original was likely a spray lacquer, but after any more than a couple of years, it will be fully cured and non-reactive to any new finish, so all you need to be concerned about is the amount of gloss you are seeking.