I believe that these are Chinese Export silver cufflinks. The initials could be either MH or HW. I have not seen a photo of these initials anywhere else. In the book 'Chinese Export Silver The Chan Collection' HW is listed as Hone Wo, second half 19c, and MH with no name but the second quarter 19c. The Forbes, Kernan, Wilkins book 'Chinese Export Silver' lists HW as Hone-Woe c. 1846 and no examples seen. There is no MH listed in this book.