Serial number is 1548000311011518 1518 represents the seat size and color, 18 black 1101 represents the month/year it was made and 1548 is the make/model. 0003 is a bit of a mystery but it may indicate the wide tree of the saddle.
The item "Circle Y Wide Tree Western Saddle 15 Seat Park & Trail Black" is in sale since Monday, October 16, 2017. This item is in the category "Sporting Goods\Outdoor Sports\Equestrian\Western Saddles & Tack\Saddles". The seller is "dcruz_n" and is located in Oakley, California. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Russian federation, Israel, Mexico, New Zealand, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Barbados, Bangladesh, Bermuda, Brunei darussalam, Bolivia, Ecuador, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman islands, Liechtenstein, Sri lanka, Luxembourg, Monaco, Macao, Martinique, Maldives, Nicaragua, Oman, Pakistan, Paraguay, Reunion.