Jerry,
Welcome to the forum! You have a very desirable gun. The Md 19 has a big following and 2.5 inch barrels are not common. However, it will be very difficult to give you a valuation without more info. Does it have the original box, documents and tools? Does it have a dash and a number following the model number? What about stocks, are they original to the gun? Excellent condition doesn't really describe the condition. If you can post some pictures here it would go a long way to giving you the information you need. Also, I'm sure there are members here on the forum who would be happy to consider purchasing your gun.