1997. I had the first made CG5 in 97 and mine was pretty sad vs the Vixen made mounts. Maybe you got a better CG5.
When I bought my CG-5, I had read that everyone was having problems with metal shavings inside the mounts and that some gears had burrs that needed to be filed off. So, before I used mine, I did a full disassembly, cleaning, inspection, and re-lube. I found nothing in that process - the internals looked great.
I purchased my C8 / GEM package from a camera store that had stopped selling telescopes. It was an old store display that had been sitting in the back corner of the store out of the way for a while. Although I would guess it is China made, who knows, maybe the mount and OTA are a bit older than a 1998 build. I see no markings to give any indication of manufacturing location.
I've used that mount regularly since 1998 and its showing signs of long use - the RA axis has some play in it.