I picked up a few (about 22) NOS gold ceramic DRAM and two 6820 chips recently. Here they are on an Obtronix board where I tested them. Out of the two 6820s, one doesn't work. The DRAM chips appear to work. These chips will eventually live on the Apple-1 Mimeo that I recently built.
The DRAM chips are MOSTEK 4027 P-3, most made in the 14th, and 19th weeks of 1976. The Motorola 6820L was made in the 48th week of 1976. Note the gold grounding straps on some of the DRAM chips.