eBay seller danfuboco. Label is a little odd since that company makes milling machines. Seller has info below although I don't really know how they arrived at that. I don't know the actual year, marked date is approximate.

Seller description:

Rare 1960's Solitron PNP Transistor Silicon Wafer 2 in.

Front label

CINCINNATI
MILACRON
CM NO. 672-1
LOT NO. 61-807-257
SUBS p___(ohm)-cm t___ mils
1st EPI.
p 34.4 (ohm)-cm t 57.2 um.
2nd. EPI.
p ___ (ohm)-cm t ___ um.

TYPE (N/N+) P/P+ N/P/P+ P/N/N+
N/P P/N P/N+ N/P+

BDV. ___

Back label

56XC109-95
REJ-20
P256-35