That's an excellent and very common concern when adding to or replacing public seating. Achieving a perfect match requires a systematic approach. First, don't rely on photos or memory. Locate the original manufacturer's specifications or purchase records for your existing benches. This is your gold standard for wood type, finish, dimensions, and hardware.
If documentation is unavailable, take precise physical measurements and high-resolution photographs in clear, natural light. Capture close-ups of the wood grain, joinery details, and finish. Contact reputable urban furniture suppliers with these details. Many offer custom fabrication services and can recreate benches based on your samples.
Always request a physical wood sample and finish swatch before placing a full order. View this sample on-site next to your current benches at different times of day. For an exact match, consider using the same supplier for the new order. If they are unavailable, a skilled custom fabricator can replicate the design. Remember, natural wood ages; discuss with your supplier whether to match the benches' current weathered patina or their original color, allowing the new ones to age naturally into harmony.