Bob,

I don´t know what part You are looking for. The only hint I can give, look at www.therifleshoppe.de. The problem is, that "Potsdam muskets" (1809/UM, 1839 and 1839/55) are not made interchangeable so You can´t be sure whether the parts of the Rifle Shoppe will fit to Your musket (I ordered two sling swivels, one fits the other not. Getting original parts is even here in Europe almost impossible.

Best regards

Marc