The four-character inscription may be read as, Bo zuo bao ding, ('Bo made this precious tripod').
The main decoration on this vessel, the band of large elegant birds with reversed heads and long tail and crest feathers, has been associated with vessels of Western Zhou date, and at times variously dated from early to middle Western Zhou. A bronze gui with similar decoration, known as the Hai gui, in Anthony Hardy's Sze Yuan Tang Collection, illustrated by Li Xueqin, The Glorious Traditions of Chinese Bronzes, Singapore, 2000, pp. 92-3, no. 28, is cast with a 43-character inscription which describes how the state of Kai was engaged in war with the Rong people of the north and which helps to date the gui to the early Western Zhou period. See pp. 22-9 for a detailed description of the inscription and discussion of the bird decoration. The body of this gui also has a similar swelling lower body.
This particular band of decoration appears to be rare on ding, and is more often seen on other vessel shapes of the period, most often gui. One other ding, known as the Shi tang fu ding, made during the reign of Emperor Gong (r. 922-899 BC) and said to have been excavated from Chang'an, Shaanxi province, now in the National Palace Museum, Taipei, is illustrated in Zhongguo Qingtongqi Quanji - Xi Zhou, vol. 5, Beijing, 1996, p. 26, no. 29. As with the present ding, there is a narrow band of similar forward-facing birds above the main decorative band, but the body has a somewhat different shape and the stout legs are surmounted by animal masks and spread at the foot. Two gui with a broad band of similar birds around the belly and raised on square bases are also illustrated in Zhongguo Qingtongqi Quanji - Xi Zhou, vol. 5: no. 54, p. 51, made during the reign of Emperor Zhao (r. 995-976 BC), excavated in 1981 from the Xizhou tombs, Huayuan village, Chang'an, Shaanxi; and no. 60, p. 57, made during the reign of Emperor Mu (r. 976-922 BC), excavated in 1961 at Zhangjiapo, also in Chang'an. Both are now in the Shaanxi Museum of History. Another gui, which has been dated to the Middle Western Zhou and has a somewhat similar wide band of birds below a narrow band of birds with reversed heads, is illustrated by J. Rawson, Western Zhou Ritual Bronzes from the Arthur M. Sackler Collections, vol. IIB, Arthur M. Sackler Foundation, 1990, pp. 424-26, no. 53.
Another ding with a similar narrow band of birds also facing a simplified mask, but with a plain lower body, and raised on short legs, is illustrated by J. A. Pope, et al., The Freer Chinese Bronzes, vol. I, Washington, 1967, pp. 184-5, no. 33. A ding of similar profile, also on short tapering legs, but with a different narrow band below the rim, dated to early Western Zhou, was excavated in 1958 in Shanxi province and is illustrated in Selected Cultural Relics from Local Museums of Shanxi - Bronzes, Shanxi, 1995, p. 44, no. 66.
Technical examination report available upon request.