Don't know the exact s/n, but I can tell you that the Savage 99C Clip mag rifle was introduced in 1965 in .243, .284 and .308. The .284 was discontinued in 1973. In 1977, .22-250 was added (discontinued 1980), while in 1981, 7mm-08 was added, and discontinued in 1981. Thus, this gun would fall somewhere between the years 65 and 73. Also, the buttplates on these guns were introduced as steel, but in 1970, aluminum was adopted. So, if yours has a steel buttplate, you'd be looking at somewhere between 1965 and 70,if aluminum, between 1970 and 73...roughly. That might help you narrow it further. That's all I got for now. My Savage book doesn't lists DOM unfortunately, and my BB doesn't list them that late. Hope this helps.
Cheers,
Matt