OK, I'll wade in here momentarily. ALL the M305/M14S receivers I have laid eyes on still had the old American pre-1994 receiver import markings on them. It seems logical to me that any receiver with a marking like that was, at the very least, forged and rough milled prior to 1994.
On Chinese made guns, M14S in particular, the first two digits of the serial number are the year of manufacture. In China a firearm is "manufactured" the year it is assembled into a product. Most I have seen were "00" or "01" which, if I remember, is around the time Marstar started drawing on their supply and offering for sale.
The older guns from the 1990's had non-standard serial numbers starting with "AL". AL = Alan Lever.
Hope that info clarifies things for SOMEONE :roll: