Those guys are top notch coblers and know a thing or two about leather!Search on the web for Potter and Sons Shoe Artisans, on their YouTube channel they explain the restoration of high end shoes and finishes...
Most all professionals use products made by Saphir Medaille d'Or made in France, another source is Horween Leather Chicago, been around and still is since 1905, have a store and excellent leather care products, interesting history in fact they still supply the pig skin leather for footballs for more than 70 years!